True, BG2's evil companions had the benefit of being total Terminators but it's fun to have more options and seeing different perspectives. BG2 leaves little breathing room opposed to BG1 which had a better rounded roster. I guess it always annoyed me that BG2 assumes you're playing the shining beacon of hope from the get-go and forces you to team with good aligned characters regardless of what you did in BG1..
BG1 had more evil NPCs, but most of them didnt have any banters and had 0 personality in general. Most of them didnt have any real quest associated with them either. So you might as well make better party members yourself and give them the same character portraits - serves the same function. Basically the only thing you'd be sacrificing is their unique voice sets.
In BG2 all companions are so well fleshed out and unique that you cannot just replace them with random goons you make yourself and still expect to have the same gameplay experience.
People often grossly downplay the importance of NPC interactions in CRPGs. To me theres a huge difference between having a self-generated character and a well-written NPC who reacts to your and other NPCs actions in a believable way. While playing BG1 I always miss the how companions would react to quests and story events in BG2. I actually cannot think of any game where NPC reactivity would have been done better than in BG2. (if you disagree, please give examples of CRPGs with better party member NPC reactivity).
