Dunno,
But if you're looking for sex, by far M4 is the most sexual. Unfortunately, you get some BEASTLY looking people in there. Not meaning to be shallow, but I've seen some 400 pound plus women (actually quite a few) at M4. (And men too - guys with keg sized bellies so big that you can't even see their cocks because the belly literally obscures their johnsons. God bless them and all, and I must say that M4 is very welcoming and inclusive, but if you have this fantasy of hot bods and a romanesque orgie, you will be sadly disappointed. That said, there are still lots of average to attractive couples at M4. In my experience, M4 is thee most sexual of all the clubs and is designed around sex and the sex scene.
Wicked is also very sexual and the eye candy is much better than M4, but it is not as sexual as M4. The couples know each other, or stick to themselves more so than M4. Xclub was the least sexual of the 3 swinger's clubs I've been to.