Don't worry if what you want to say has already been said, keep the discussion going by all means, it's good to keep this thread healthy!
Oh trust me when I say If I went into it I could say/write a lot. Think I made that clear in the Shadowheart/Halsin/Astarion threads.

But I'll say this in regards to Karlach. Ever since EA I was interested in experiencing her story. (I still remember that theory about her being a paladin/or was it a fallen paladin in the service of an archdevil) Hell my first playthrough/MC went with Karlach only to end up with...well you already know how it ends.
Three things that come to mind at the moment that I would like to see changed or improved: (that aren't the ending/fixing her engine, that one is obvious)
- I might be in the minority here but her use of the word 'motherfucker' kinda takes me out. No one in the whole game uses it and its just sticks out like a sore thumb. Fuck and other expletives she uses are fine.
- Gortash and his whole involvement. I would really like to see this part of her story expanded. I mean Shadowheart gets a whole temple with Viconia and Shar, Astarion gets a mansion/crypt and Karlach gets a hallway that you just walk into. Disappointing to say the least.
- I would like for her personal quest to be fully fleshed out, getting random pieces of iron and talking to Dammon just isn't enough for me. It rather pales in comparison to the other companion quests.