Difficult choice.

Ultimately, I went with Artillerist...the fact that your Eldritch Cannon can be wielded or be mobile is nice flexibility...the bonus action economy is GREAT; letting the Artillerist cast their spell or use their Action creatively...the options for Eldritch Cannon are tactical and fun...the spells are fun...the damage is fun...

It's fun.

HARD choice picking between Artillerist and the Battle Smith, though...the spells of the Battle Smith are undeniably useful...the Steel Defender is a potent ally and provides meaningful support...and the variety of martial weapons that can benefit from the Artificer's Infusions is ABSURD and makes my head spin...javelins of returning...winged boots so you can smack flying enemies with a warhammer...boots of speed that lets you deliver the best rapier thrust from across the room...double rocket fists...

Hmph...this happens every time I plan an Artificer...Artillerist & Battle Smith are too competitive.

That number of infusions is one reason why I love Armorer so much.  Not only do you get extra infusions, you get what amounts to a magical rapier that doesn't count as magical, so you can legally infuse it, and you get extra infusions, so you don't mind at all being selfish about infusing your armor.

Being AC 22 as a class feature is just damn compelling.

The Battle Smith is a definite favorite of mine. Honestly, any class or feature that allows a pet, companion or mount as part of the package tend to be favorites of mine (Beast Master and Drakewarden Rangers, Find Familiars, Find Steed, Tasha's Summons, Cavalier Fighters, ect.)

Artillerist is a close second though, if only because playing a cross between a Krogan "Scientist" and a Blastoise was WAY too much fun.

Personally, I like Armorer best. I think that it has a good mix of offense and defense, as well as having some interesting roleplay opportunities.

Armourer: Massive AC possibilities with enhanced defence. At tenth level you could have 22 AC when you use infuse both your shield and plate armour. Also the abilities stack really well.

artillerist also has a companion of sorts with their eldritch canon. I am currently playing a character with a canon and a homunculus. its a lot of fun if you like doing that @JustDungeoning

Artillerist.

My Homonculus can fly with my turret around the battlefield, turning it into a mobile healbot or gunship. I've flavored it to look like a ball drone with Davinci airscrews for rotors.

Casting Web to ensnare a ton of enemies and then torching the area with the Flamethrower to hit everyone for extra fire damage is a fun combination for a single turn.

Being attacked by a group of vampire spawn and using Thunderwave on a pile of wood to shatter it into large flying splinters and staking the enemies around me.

Artillerists have amazing action economy, especially for bonus actions. Restoring up to 13 temporary HP to anything you want within ten feet is absolutely gamebreaking and even scales pretty well with higher levels. The flamethrower is basically Dragon's Breath and ballista is a 3d8 force cantrip, both as bonus actions.

But my favorite ability by far has been able to put Scorching Ray in my Spell Storing Item, either a secondary pistol or my Homonculus.

Quote from EurobeatJester >>

Artillerist.

My Homonculus can fly with my turret around the battlefield, turning it into a mobile healbot or gunship. I've flavored it to look like a ball drone with Davinci airscrews for rotors.

Casting Web to ensnare a ton of enemies and then torching the area with the Flamethrower to hit everyone for extra fire damage is a fun combination for a single turn.

Being attacked by a group of vampire spawn and using Thunderwave on a pile of wood to shatter it into large flying splinters and staking the enemies around me.

Artillerists have amazing action economy, especially for bonus actions. Restoring up to 13 temporary HP to anything you want within ten feet is absolutely gamebreaking and even scales pretty well with higher levels. The flamethrower is basically Dragon's Breath and ballista is a 3d8 force cantrip, both as bonus actions.

But my favorite ability by far has been able to put Scorching Ray in my Spell Storing Item, either a secondary pistol or my Homonculus.

 Its a good thing your DM lets your homunculus carry your eldritch cannon... the homunculus and cannon are both tiny constructs (I'm assuming your cannon is tiny and not small).

Putting a SSI loaded with Scorching Ray in your homunculus's hands is a banger idea!

what I have recently realized is that you can go invisible and use your cannon or homunculus to attack or Deliver spells. one of my favorite builds is my artillerist artificer who has a homunculus and a cannon. the tactic is simple. cast aid in the beginning of the day giving more hit points to both myself and the homunculus (if I can hold off and know a battle is coming I will sometimes be able to get my cannon too). I can send my cannon over in one direction and have my homunculus go in another direction. I start combat with shooting fire bolt with spell sniper. I use my movement to gain cover. bonus action attack with my cannon or with my homunculus. next round invisibility while attacking with either my cannon or homunculus (invisibility sticks because I am not attacking or casting a spell). in open setting this can be an awesome set up as it makes it look like many enemies are around when it is just me. homunculus has a range of 120ft with 30ft firing range, the cannon has a range of 60ft (with 120ft range with eldritch cannon) and I have 240ft range. I can also just use the homunculus to aid allies with spells while I stand back and use the defensive cannon to boost the more range allies. currently only level 5 but it is a lot of fun. this is also a decent trick with battle master but you are putting your steel defender in more harms way but then he acts as your shield while you stay back and pepper the enemy.

Before Tasha's, definitely the Armorer. After Tasha's, there's not really any other choice but Battle Smith, at least for the high-powered game my friend group was playing.

It was funny switching from Armorer to Battle Smith. I lost 1 AC, but I actually tank way harder between me and the Steel Defender, and the DM is more inclined to go after me now for some reason. Plus I got Shield back and a whole suite of spells that make me as annoying as a paladin! Also massively boosted my damage, I switched out some feats so I have firearms expert/sharpshooter with pistols. I had homonculus with my Armorer, but the Steel Defender works as a homunculus+, so losing the two infusions slots for Arcane Jolt was wonderful. It's much nicer to be able to use any weapon now also, to not have to wait through a short rest just to be able to use a ranged weapon with a decent accuracy. I might grab archery fighting style for my final feat for the lulz. The Battle Smith is superior in every way ¯\_(ツ)_/¯

Quote from RygarNorixious >>

Quote from EurobeatJester >>

Artillerist.

My Homonculus can fly with my turret around the battlefield, turning it into a mobile healbot or gunship. I've flavored it to look like a ball drone with Davinci airscrews for rotors.

Casting Web to ensnare a ton of enemies and then torching the area with the Flamethrower to hit everyone for extra fire damage is a fun combination for a single turn.

Being attacked by a group of vampire spawn and using Thunderwave on a pile of wood to shatter it into large flying splinters and staking the enemies around me.

Artillerists have amazing action economy, especially for bonus actions. Restoring up to 13 temporary HP to anything you want within ten feet is absolutely gamebreaking and even scales pretty well with higher levels. The flamethrower is basically Dragon's Breath and ballista is a 3d8 force cantrip, both as bonus actions.

But my favorite ability by far has been able to put Scorching Ray in my Spell Storing Item, either a secondary pistol or my Homonculus.

 Its a good thing your DM lets your homunculus carry your eldritch cannon... the homunculus and cannon are both tiny constructs (I'm assuming your cannon is tiny and not small).

Putting a SSI loaded with Scorching Ray in your homunculus's hands is a banger idea!

 They're both tiny objects(I have my turret flavored as part of a gauntlet/arm cannon that can power up, so I don't use the Small option to stay consistent).

The homunculus has a strength score of 4, but because it's a tiny object the amount of weight it can carry gets cut in half. That's still 30 lbs, well below what a tiny cannon would weigh. That's strong enough to airlift a shapeshifted Druid or possibly a creature with Reduce or polymorph cast on them!

Depending on how you interpret the rules, you should be able to use the homonculus itself as the SSI. The rules state it can be anything that you can use as a spellcasting focus, and anything you create as an infusion can be used as one! I'm experimenting with putting Cure Wounds in mine, and having it zip around the battlefield so an ally can snatch it out of the air and use it if they need to.

Alchemist. Because I like being a healer/support role without being a cleric.

Armorer but sadly it is slightly underpowered compared to battle smith if you want to do anything with it that's not playing straight into the pre-determined modes. If it had "battle ready" and you got 1 free armor infusion at low level it would be much better.

Artillerist and Battle Smith are my favourite two. The cannons for Artillerist and the Steel Defender for Battle Smith provide versatile extra action economy, and both subclasses allow for fun flexible builds.

Alchemist is interesting, but a bit underwhelming compared to other classes (although I suppose it does have some niche uses; in a campaign with lots of curses and afflictions, 5 uses of greater restoration without expensive material components could save the party).

I could nit-pick about Armorer all day. It leans too much into the 'Iron Man/Hulk Buster' aesthetic for it's own good imho.

Quote from RuStyMoNkey_964>>

Armorer but sadly it is slightly underpowered compared to battle smith if you want to do anything with it that's not playing straight into the pre-determined modes. If it had "battle ready" and you got 1 free armor infusion at low level it would be much better.

You sum it up nicely; the two Armor Models lock you into two playstyles and two weapons. The lack of a "Battle Ready" feature for Armor that allows it to use INT for other weapons is disappointing.

The Thunder Gauntlets in particular are problematic - how do they work with two weapon fighting, and the Duel Wielder feat? Since the Thunder Gauntlets 'magically' emit their distracting pulse, does that mean they are already magical and therefore cannot be infused? (The wording of the Level 9 Armorer feature implies that they can be infused, but it isn't totally explicit).

Crucially however, the Armorer is meant to be a tank as you can easily stack AC. But most classes that act as the party frontline with high HP/AC are able to tank because their damage output is a threat to enemies (Fighter's multiple attacks, Barbarian's rage damage, Paladin's smite etc). Armorer has no strong equivalent. It relies on methods like the Thunder Gauntlet properties, Booming Blade and picking up the Sentinel feat to tank reliably.

TLDR: As RuStyMoNkey said, Battle Smith is a better alternative to Armorer, both for aesthetics and mechanics. Sorry for the wall-of-text rant. This is all just my opinion :)

I like the Armorer, and I'm not a big fan of Ironman.  For me it's how the character looks and/or feels.  I like the idea that my Guardian punches with Thunder Gauntlets, even if they aren't the strongest weapon... they're good enough.  I like the feel of an Infiltrator extending his hand and blasting lightning into a foe.  It's cool, and no I don't plan on using a chest mounted lightning launcher because that's weird to me.  I like the versatility of being able to switch between armor types so that I can Tank OR Sneak.

I find the Armorer to be a fun base class to build a character around.  I've never been a fan of multi-classing, and I prefer to run just my character, without having a familiar/homunculus/cannon/steel defender to also look after.  I like keeping things clean.  There may be some game mechanics that lead to short-comings in the class, but who cares?  I have my fellow party members, feats, spells, and skills to overcome such deficiencies.  The flaws make the character, and they make the game fun.

No, I'm not choosing this class because it is flawed.  I'm saying that the flaws it has are more interesting to me than the flaws of other classes.  How can I do more damage?  How can I fight at range when I'm a Guardian?  How can I fight in melee when I'm an Infiltrator?  Which spells support which armor type?  What feats should I take that would be interesting?  Am I a mechanic or a Tank or a Blaster or something else?

I haven't actually played an artificer yet, but Armorer. 'Cause eventually, you can be Iron Man.

Oh, and punching people with pure thunder. Yeah, that's a big one.

i love the versatility of Battle Smith, and their flavor as a tanky combat medic. Alchemist has the best flavor/RP imo, but how the experimental elixer feature works needs a little tuning by you and the DM (like bonus action potion drinking). Its just annoying having to constantly remind the party about the elixers you made, and also takes the real agency away from you. Even though you made the potions, they have to remember/choose how and when to use them.

I know it's not a popular opinion, but I actually like the Alchemist. Firstly because it annoys people to like it, but also because while the other three sub-classes are also a lot of fun, they're also very combat/damage oriented. Alchemist is a little strange mechanically, but it lets the artificer lean more into support in a Bard/Cleric like way, which makes it one of the most different of the sub-classes.

People argue over whether Alchemical Savant works with spells that don't have material components, but that's always annoyed me, as nothing in the rules for a spellcasting focus actually says a spell must have material components before you can use it (the focus just normally doesn't do anything extra unless the spell has them). Assuming Alchemical Savant is actually intended to be used, it's a good feature, especially in the healing support role as you can get more healing out of your half casting; if your DM gimps the feature for no reason, then yeah, it's a bit weak.

A lot of people also like to hate on Experimental Elixir but half of them are always useful, and the other half you can usually make work; being able to just create bless-lite, healing and AC potions on demand is underrated IMO, though it depends how easy it is for your party to get potions normally.

It also probably demands you talk to your DM about crafting more than the other artificer sub-classes, so that you can make the most of your alchemy, but it's a sub-class where you definitely want to lean into the extra crafting for RP IMO, but then that's the kind of stuff I enjoy.