For my Skypies I have no gender preferences! Both genders are welcome to do language exchange with me. I have more experience with male Skypies, but that doesn't mean anything. I like serious language learners who have a broader horizon being able to talk about more topics than only languages and language learning. Besides this I have no age preferences either for language partners. Fasulye
In Japanese there are still significant differences in the ways men and women talk so it is probably best to study with a person of the same sex. But I have found it is far easier to find women who want to study English so I just take what I can get. Generally, geography and schedule is more important (who lives nearby and is available to meet when I'm free).
The differences are pretty minor, imo, but that may be good advice for a complete beginner. Oh - if you learn like Benny Lewis that's probably a good idea too (learning mostly from the conversation of your partner even in the beginning).
But he doesn't do that! He sits with his head in books, like every other successful learner, then says "oh, you don't need to do this." [Goddammit -- I've just been successfully trolled by the site admin.]
I've just heard Japanese politely mock (is that possible?) Western expats who get most of their Japanese from talking with their girlfriends so it is something I keep in mind. It is probably more an issue if you are speaking in person, which is my main way of meeting exchange partners, rather than writing.
Sure. Not only are they getting their Japanese from their girlfriends, but if they are like most expats, their Japanese is very basic. You'll find little if any advanced or even intermediate learners who haven't figured out that specific problem.