I'm about halfway through my final run of BG1 as I just entered Baldur's Gate. My party is Imoen, Viconia, Jaheira, Khalid and for the first time Kivan.
I never realized how badass Kivan was. His THACO is so low he never misses, 3/2 attacks per turn and hits for about 15 with each shot.
Since it's BG1, there aren't that many enemies with resistance to basic weapons so he is pretty good. Although, it reminds me why you don't want archers in BG2.
I'm already planning on keeping Imoen, Jaheira and Vicona for BG2 and adding Aeris to the mix (I just can't say no to her). I'll probably pick up a character I never used for my last slot again.