This has probably been said before, but it's annoying when Viconia leaves, despite gaining a ton olf gold/magic items/success, because you saved some farmer's cow from some xvarts. Like, what's she thinking, omg, that's the last straw CHARNAME. You saved that cow and I will stand no more, fool!
And it's not like Jaheria, a druid, and Kivan, a ranger, get bent out of shape if I go about systematically slaughtering every squirrel, cow, and horse in the game for the lulz. And yet, Viconia cares about saving a cow?!
I get a low reputation level causing good party members to leave. They have consciences and morals niggling at them. Evil party members don't and should be selfish enough not to care what CHARNAME is up to so long as it benefits them, because they're selfish by nature. I mean, don't the evil characters enjoy being able to buy items from shopkeepers at a discount?
If anything, please institute a bribe system. Have the evil character demand gold or something to remain with the party. If you don't want to pay or can't afford the bribe, the evil character leaves. That should be simple to implement, right?
If you think this cheapens the roleplay experience or the spirit of the game, then impose an experience penalty on the bribed evil character or something. I mean, evil characters get to bribe churches to magically keep their reputations up without having to do legitimate "good" acts, so why should my paladin be force to quietly murder townsfolk so Viconia doesn't walk off because I saved a friggin cow? Or why should I need to make poor Imoen intentionally botch a pickpocket attempt so I can stick my tongue out at some guards and run away?
Seriously, the reputation system in general is pretty nonsensical and one of the weakest systems in both games. You get the same bonus for saving a cow as you do for saving the livelyhoods of an entire town. You cap out at 20, even though you go on to do greater and greater things. Like, once you save a few cows and recover a few corpses for people, you're reputation is as good as it ever will be, despite some of the epic things you do over the course of the two games. It's just aggravating.