[I'm taking this from what I had wrote in a different thread that became kinda swamped with drama]

I am kinda heartbroken about the loss of Half-Elves. They were my default for the longest time, and their unique space in the world, reflected by their two +1's and then +2 Cha, was also very nice. I don't like getting rid of them. Half-Orcs weren't as effected by this loss of half-race. Most people I knew that played half-orcs only did cuz "fUlL oRcS aRe EvIl" or they didn't like the idea of how they came to exist and how it may not have been consensual. Half-Elves had always been a special niche that can't be accurately as demonstrated by "play using the elf stats, but aesthetically call yourself a half-elf". Also, half-elves, to my knowledge, wouldn't be able to trance lore-wise.

On that same vein, the half-y rules seems kinda stupid, unless I'm misreading them. 1DD is saying "play using x stat-block, but you can customize them aesthetically." Of course you can, they're your character. But as stated previously, playing a half-elf with a full elf stat-block doesn't fit well. Unless it's to be interpreted you can mix and match lineages features. But even that will never compete with the same niche that Half-Elves serve now.

Dragonborn, despite just getting a revamp in Fizban's, changing to "now every breath weapon is a cone" seems kinda dumb. Stop switching it around, WotC. I for one also feel if it's something you can genetically do because you're some sorta dragonkin, you should be able to shape it, so like one use of it could be a 15 foot cone, then the next you could have it be be a 15 foot line, but mechanically idk how game breaking it would be.

Tieflings, at least from what I've been told, going back to a catch all for "fiend-blooded" instead of just "devil-blooded" is something that at first didn't sit right with me, but apparently older D&D that's what they were and it wasn't 'til 5E that "Tiefling" meant specifically Nine-Hells-blooded. I will admit, I'll miss all of those subraces. (RIP Zariel Tiefling).

Ardlings are neat, but I'll still probably default to my Aasimar pretty-peeps.

Tavern Brawler is still a bad feat. 1d4 is a bad damage die and pales in comparison to "Fighting Initiate - Unarmed Fighting". Also "Furniture as weapons" should go back to "Improvised weapons" instead of using words that only tie it to furniture.

The last issue I have with a lot of these newer changes is the removal of "Sunlight Sensitivity". Drow/Duergar/Svirfneblin all being bred from Underdark natives would, logically, have eyes that would not work terribly well in the bright surface light. And mechanically "Is sun out? Yes. Disadvantage on Perception." is fairly easy to understand, and not terribly harsh.

One rule that isn't as agreed on, varies on DM, and really needs to be visually nipped in the butt by WotC by like, a video on their youtube or on here even, is Darkvision. Because you'll have players who treat it as Nightvision, you'll have DMs who say "it's night out and it's pitch-black, you can't see anything, and it's just really something that I feel a visual representation of what it's supposed to LOOK LIKE would stop the age old argument. Also, and this was pointed out by my DM, way too many lineages/ancestries have it. It's too commonplace. I can only think of Humans, and Halflings that DON'T have it.

EDIT: I also feel, unless I'm misreading, that it's now intended that any creature within the same creature type (Humanoid, Fey, Dragon, etc.) can interbreed and have viable offspring. I'd love to hear feedback on that take.

Just some thoughts.

1. It references choosing races from 5e, so you can still have your Half-Elf if you like.
2. Reading it, it does say that you pick the statblock of one race. I'm not liking this, that you're limited to playing normal races, it's just that you can mess around with cosmetic stuff. If they're going down the root of custom half races (I really like that idea, btw), then it would be better if they provided a mechanic to create one using the traits of both. Either a point-buy system (which would be complicated, so making it for experienced players but amazing) or a sidebar explaining what each race contributes to an offspring of mixed parentage. I think I'll be keeping the other Half-Elfs and Half-Orcs. 
3. I've spoken on Sunlight Sensitivity before. I've only looked at it on Drow and Kobolds so far, and one was handled really well and the other was awful. Kobolds were amazing, because the advantage (Pack Tactics) was able to counter SS, it shaped your behaviour, but didn't restrict it. You could still go out in sunlight, but you had to use PT to cancel the disadvantage, which provided a lot of flavour. Drow was awful, though. There was no easy or reliable way to counter it. So daylight campaigns, for me at least, became a no go. I wouldn't play them (as a Drow) because my character would suck. I would play ones in campaigns without daylight, like Rime of the Frostmaiden, but then you essentially don't have a downside, just the OP upsides. Unless they found a way to do a job similar to Kobolds, then I'm not sure it was tenable to keep SS because it was just bad game design.
4. From what I remember, about half the races (overall) have Darkvision. Dragonborn, Halflings and Humans don't get it in PHB. Unfortuantely, it was overdone. It stopped being a boon for the races that have it and started to be a punishment for those that don't. As long as you had at least one of the right casters, they could cast Light and the dynamics worked better, but yeah, too many having the advantage to make it special.
5. From what I read, it's just humanoids that can interbreed, at least that's talked about.

So first of all this is all up for discussion and debate so my go to is play test it, see how it works. 

Now let’s look at what the new rules have done, first of all even if you had a half elf race there ASIs are now no longer tied to race at all. Everyone gets the same 3 floating ASIs to spread about either as 3 1’s or a one and a 2 based on there background. Now that’s a really really strong step forward, no longer tying the idea that Elves are clever, orcs are Strong etc. it also means that the table will be far better balanced and people will choose a race more because they have a story they want to tell rather then because they want to play a bard, or a wizard or because this one gives me a total of +4 asi and this one only +3. Balance is a good thing at the table. You suggest the reason you like your half elf is the stats it brings, not the storyline options or opportunities. We now open up DnD to storytelling more while still allowing the min maxers to optimize a build. 

We also now get the chance in RAW to do what so many have done for years, create a half dwarf half gnome, half elf half Tiefling. It encourages DMs to think about the wider world and the different variations of race you can get. 

Now, I do think the half race rules will be tweaked a little, right now it feels like you should be able to pick and choose between different aspects to take from each race rather then have to just pick 1 but, that also makes balance harder, people will game the system to make a half x half y because they can work in a really cool set of abilities together. I also think you will, in the real book, get a ton of background about half races, how they struggle to fit in etc so it will feel like more of an option then the few lines of mechanics included in the UA and, I believe that you will find there will be level 1 feats that allow you to make a character similar to your half elf. 

The biggest step forward however that people seem to be missing Orcs are in the PHB as a playable race. No longer the go to low level bad guy if a DM has a lawful good orc in the party they are far more likely to start world building in more shades of grey. This is a subtle but powerful indicator that, combined with monsters no longer having set alignment, will breed more creativity in campaign and encounter design. 

Tavern brawler, yep on paper looks a little weak, I imagine that will receive comments from players giving feedback, even if it’s “players never pick it”. But that’s the point of this take feedback and improve.

Likewise dragon born, I can see breath weapons being tweaked again and again, it is possible that the Fizban changes unbalanced them and wizards are now trying to correct that but I imagine this will flux and change over the next 18 months. 

The way races breed really doesn’t matter, love finds a way as it where and I can see dwarves falling in love with dragon born, or gnomes etc. in fact it makes much more sense then “only orcs and elves can breed cross race”. I wouldn’t get too fixated on that, players have been doing it for decades (my last table I had a half Tabaxi half gnome pc playing). 

Sunlight sensitivity has always been one of those rules that DMs either ignored, or it stopped players taking the race. But I would also point out that there are no drow or Duregar options there yet, maybe this will be a feat, take sunlight sensitivity for other benefits? Although if I think I am right sunlight sensitivity was removed in MMM. Again give your feedback. 

But focus on the positives here, players are being given far more choice and flexibility, the backgrounds can be really easily templated out to make a host of fair balanced customizations possible. Players will no longer be out off by a race because it is not optimal for the class they want and, tables will be better balanced. 

There is a Drow in the document. It's an elf lineage.

Tavern brawler, yep on paper looks a little weak, I imagine that will receive comments from players giving feedback, even if it’s “players never pick it”. But that’s the point of this take feedback and improve.

However, remember that this is now a Level 1 Feat, which should be more or less balanced against Crafter and Musician.

In my opinion, Lucky and to a lesser degree Magic Initiate are a bit over the top for a Level 1 Feat.

I am seeing now that Dragonborn's change to "everyone gets a cone" is fair. I do miss the backpedal of changing it to a full action again, instead of replacing an attack.

I still standby that I'll very much miss all the Tiefling options we used to have.

Half-Races I feel we'll get used to... but it still sits wierd.

Tavern Brawler is still lame, frustratingly so.

Quote from Scarloc_Stormcall >>

Now let’s look at what the new rules have done, first of all even if you had a half elf race there ASIs are now no longer tied to race at all. Everyone gets the same 3 floating ASIs to spread about either as 3 1’s or a one and a 2 based on there background. Now that’s a really really strong step forward, no longer tying the idea that Elves are clever, orcs are Strong etc. it also means that the table will be far better balanced and people will choose a race more because they have a story they want to tell rather then because they want to play a bard, or a wizard or because this one gives me a total of +4 asi and this one only +3. Balance is a good thing at the table. You suggest the reason you like your half elf is the stats it brings, not the storyline options or opportunities. We now open up DnD to storytelling more while still allowing the min maxers to optimize a build. 

We also now get the chance in RAW to do what so many have done for years, create a half dwarf half gnome, half elf half Tiefling. It encourages DMs to think about the wider world and the different variations of race you can get. 

Now, I do think the half race rules will be tweaked a little, right now it feels like you should be able to pick and choose between different aspects to take from each race rather then have to just pick 1 but, that also makes balance harder, people will game the system to make a half x half y because they can work in a really cool set of abilities together. I also think you will, in the real book, get a ton of background about half races, how they struggle to fit in etc so it will feel like more of an option then the few lines of mechanics included in the UA and, I believe that you will find there will be level 1 feats that allow you to make a character similar to your half elf. 

 

Maybe I am just looking at this wrong. But to me, there was fleshed out story lines of why certain races didn't happen to go into certain professions. Especially that certain species just had alien thinking compared to others, and someone who was a certain class would be considered a heretic or an outcast within their community. This didn't mean you were truly restricted from playing a class/race combo, but there were certain disadvantages of doing so. And for me that ASIs made sense because of genetics and balancing acts. Humans were probably the only outlier, but most people wanted to play something different and humans have really no class advantages that excited people.

But with the new system these changes feel very bland and for lack of a better term, they remind me of game avatars. No real fit or function, but they are pretty and help for a player to self identify. I have seen the use of this taken off in games like Everquest, and fortnight. I never cared for the whole "skin" idea for characters, instead of creating fully fleshed out characters that tell a story, and can give fodder to the DM for their story telling.