I'm somewhat biased when it comes to angels because most of the experiences I heard (http://etl.stanford.edu/) were almost always homeruns. Sure there's the down in the gutter claims every investor tries to sob about where they lose money but let's be honest wouldn't it be great if someone gave a talk and said how much they lost (and how much they're continuing to lose) by attempting to get rich quick.
So far bootstrapping appears to best way of weeding out the shitty angels who haven't been in the game for a minute.....it's a pleasure to not deal with someone wanting to give you a check while telling you what their expectations are for YOUR business not their 10k+ check.