I have a Rogue Arcane Trickster that started taking levels of Bard and will continue to do so for the rest of the campaign. Our DM has a loose plan for the the rest of this arc and estimates that our characters will probably achieve level 15 at the highest, assuming we survive until the end. Currently I am at Rogue L9/Bard L2 so the next time we level up I will have to choose my Bard subclass. So I might eventually achieve Bard L6 but if I do it will be at the very end of the campaign.

I have been of the mindset that I will go College of Lore but since my character will never achieve high levels of Bard is that the best choice? One of the advantages of the Lore Bard is of course the extra skill proficiencies but between being my Rogue class, my background (Criminal), and my race (Elf) I am already pretty loaded in that area, so gaining the additional 3 is nice but not really a huge boost. Cutting Words is a pretty good feature but if I even gain enough levels to get the coveted Additional Magical Secrets I will barely be able to take advantage of it if our DM's estimation of the remaining campaign arc is accurate and holds up.

So I am looking at the other subclasses now to try and determine if I should choose something other than Lore . I don't know that the martial subclasses like Swords or Valor are a great fit but am open to it if anyone builds a good enough case. Whispers, Spirits, and Creation are not of particular interest but sell me on it if you love one of them. I am looking at Glamour but looking pretty hard at Eloquence. The 3rd level features of Silver Tongue and Unsettling Words may be a better addition to my character than additional skill proficiencies and Cutting Words.

Any feedback is appreciated (well, unless you are trolling). Has anyone else played an Arcane Trickster/Bard at similar levels?

How's your character's Charisma and what kind of role do you want them to play?

Eloquence is ideal if you want to be the party's "face" (the one who does talks the party into/out of many situations), Unsettling Words is also a great combo for the many control spells in a Bard's spell list as you can make it a lot harder for an enemy to pass their save.

Glamour's Mantle of Inspiration is just great for bolstering the party in the combat; Enthralling Performance is fun but quite situational.

Lore early on is definitely all about Cutting Worlds and the extra proficiencies; it's perfect if you want to excel at skill rolls, though for a Rogue you could also go to 11th level for Reliable Talent which makes your proficient skills ridiculous.

Spirits is interesting; I mean Guidance alone can be worth it as I love that spell, and while Tales From Beyond is random, you can roll it in advance because they don't apply until you bestow them.

Whispers is possibly the most Rogue-like Bard, as the psychic blades somewhat enables you to continue your Sneak Attack progression despite multi-classing. It definitely leans into the more stealthy/sinister aspects, though you can play it off as just being extra compelling (can be extra intimidating when you want to be).

Whatever fits the character best though is what you should go for; that should always be top priority IMO.