I think I've been incredibly lucky, over 40 years playing in bands, all bar one have been pretty much up together and ok players, some very good.
The one that was flakey used to smoke a lot of weed, didn't have a drumkit (in this country), was a day late for a gig once, and also lost all the money he had taken out of the cash machine for the weekend in the course of a 200 yard walk from said cash machine to the venue.