if I'm truly buddy diving, I'm extremely picky!! I usually consider myself a solo driver reguardless to whomever is diving around me (meaning, I'm there for them, but won't count on them to be there for me). I'd say there only a very small amount of people out there I consider buddies, and they each have something different to offer.
As a DM on a boat, here's what I see most of the time. I can't honestly say one gender is better than another (as far as diving). I've seen the "Rambo" divers in both sexes, same with the "race-to-win" people, and the "go as slow as you humanly possible can". Honestly, it's such an equal thing. I do prefere my SI with the guys. They seem a lot less fussy about whatever knew thing there is to whine about then the ladies (unless it's an all chic dive, funny, when you exclude the men folk, most of the chickies dont do all that crappy cry baby, whiney stuff)