Again it's my opinion but i think that would make big difference:
1. Colors - many people see the colors in BG3 and instantly compare to DOS2, but it's true, and i think it's because of so much similarities with light green, too bright. if you look at BG1 the colors were definitely darker green
2. Party control - i think in old BGs had it right, click on portrait that avatar was selected, select 2 or 3 use mouse, select all you get the idea. this chaining HAS TO GO, i spent yesterday most of the day playing, my wrist hurts now. and if you say it worked in DOS (not really) and that's precisely why it shouldn't be here.
oh, another thing:
Space bar - it's great that you can speed up conversation, but do not let it to select another line.
