Thanks for all the thoughts on this. Interesting perspectives all around.
I would say my favorite scenario is M/F, for a number of reasons, the chief one I think being that I came into ryona already a fan of kink and BDSM, and the M dom, F sub dynamic is one I've always liked, for some reason. Anyway, that seems to have carried over here. Also M/F ryona is the combination that most flies in the face of traditional depictions in the mainstream where the female character usually wins if she's not a damsel, which adds yet another exciting thrill to the mix.
A few clarifications:
As I've stated before I'm not a fan of M/F ryona where the guy is physically overpowering from the start compared to the girl, in such a way that she is at a disadvantage from the start. The only way this would work is if she has some sort of powers that make up for it. This is a preference both because I like scenarios where the girl loses fairly, and as a result of being an inferior fighter, rather than because she's unfairly matched, and because I'm much more comfortable with matches such that the girl loses fairly to an opponent who happens to be a guy, rather than her being beaten up by a brute who she had no chance against anyway, just to bully and abuse her. Thereby avoiding similarities to real life abusive circumstances.
Hopefully some of this makes sense. I just like to avoid reminders of real life abusive situations, and instead have a set-up where no one starts off at a disadvantage, and the winner(s) are determined by skill, not by gender.
All that being said, I'm quite a fan of F/F also, and actually have done that exclusively in my RPs, and half the time in my stories, since I'm a lot more comfortable putting in intense elements when a woman is dishing said elements out to another woman. Plus I like it for other reasons, including Yuri aspects, as I've touched on before.
All good stuff indeed.