Neither, really. But in a "gun to my head and I have to choose" situation, I'd take the guy who stinks but is a decent guy. He can always practice and get better but an ass will always be an ass.
We're in the process of auditioning for at least a 2nd guitar player and possibly a keyboard player now and one of the guitarists I talked to looked good on paper and seemed to have a lot of really good experience. As a player, he might have turned out to be the best one, but I got increasingly bad vibes from him and told the rest of the band about it. When I called a few days ago to confirm that he was still going to be able to come out to play with us (would have been tonight, actually), he just rubbed me the wrong way and I told him we aren't looking for someone to come in, take over, and permit us to be his backing band - as long as we can continue to satisfy him. Not long after that, he sent an insulting email and said he wasn't going to bother with us. The only thing that bothered me was the time and effort I put into finding him and trying to get him scheduled to come in. I wasn't at all bothered by not playing with him.
I'm into music for the fun of it. If I have to deal with personalities that are going to take away from the fun, then I'd rather not be involved with them. But, if music were my living, then I'd probably have to be a lot more forgiving of the personality issues. That's no different from my day job - I might not like you or our personalities may clash but if we can respect each other and keep ourselves focused on getting the job done then I can tolerate most anybody at work. I don't have to like it but I can be adult about it and deal with it. Thankfully, I don't have to be that way with music.