Not to be wet sponge, but I've had good and bad buddies of either gender. I'm lucky that my wife is an excellent buddy. Doesn't crowd but doesn't wander away either. Carries her own gear. Biggest problem is getting her to take the lead on dives sometimes, instead of just following me. Our air consumption is about the same (could be because we're both 5' 9" although I'm about 10 punds heavier).
OTOH, I had one lady I dove with a half dozen times (before my wife certified) and it was like being in a race. If I paused to look at something, she'd be 15 to 20 feet ahead of me and no amount of discussion on shore ever got her to slow down. Of course, maybe that's beacuse I'm one of those "aging" males and just can't keep up.
It is great to see the number of women that are diving now. I was up (just to dive) at an OW/AOW weekend recently and nearly half the students and 40% of the certified divers there were women.