I've seen far more projects pushed to a successful completion by assholes than "nice" people, so either assholes are statistically much more productive (making your "better" person basically irrelevant) or we have a vastly differing definition of "asshole".
I might agree about the better person being basically irrelevant, but I've seen a lot of projects run into the ground by assholes - I guess my basic point is that being an asshole is only weakly positively correlated with being a competent manager.
