I think both of them definitely have their uses. I default female as I think that they're more fun, but I'll do male sub stuff in rp sometimes. Male sub Female Dom seems to be the most popular from what I've seen around, mostly as males like to project themselves into the sub roles for those. Though really it comes down to personal preference. Some people don't like M/M or M/F, some people don't like F/F or F/M. I typically find the kink content more important for me than the genders of dom and sub.

I do tend to lean further onto content with males but yeah either is fine

Maledom on femsub is my personal favorite but I think there's an audience for both