Have been to Decadence NYC  and the women range in age and mainly older guys

the name of the bar is Checkers? It's in midtown west and there are only older couples who swing. I had THE best time there at Halloween one year. The club is big and has lots of rooms and a nice dance floor. Really fun!

The clubs I've been to have different people hosting theme parties on different nights and thus draw different crowds.

I like Pendulum when Juliette hosts.  That's their Leather & Lace party.  Combination swinger/fetish.

I went to Decadence for their Thursday night group play party and it had a great mixed crowd.

Some of these clubs gave MILF nights, so if you are looking for an older crowd, I'd suggest starting there.