Age doesn't at all matter to me. I would sleep with a much older man or women. I'd be less likely to go over 50 with a women until I age closer to that, but I would be with a man who was over 80. I like aged men for some reason.
I'm 11 years older than my wife - so I suppose that's her limit. As for me, I dated a girl just 2-3 years older. It wasn't a hard limit, its just my experience.
I am not attracted to people older than me. I don't know why, but I can't even imagine sleeping with an older guy, even if it is only a few years older.
My Dom is more than 20 years older than me. I don't think I would like to be with someone much younger than me at this point, but older doesn't bother me.