I have to agreee with @Arpig
This is a thought that has been going through my head lately, as my daughter gets older my minimum age increases too. However on the OP's original premise that older women are more reserved, I find this the opposite. I am quite good at getting twentysomething ladies to be more experimental, but mature ladies are usually open to anything and everything from the outset!
I'm not entirely sure what you are asking...but I think its what is the age preference of male doms...so that is the question I will answer.
First of all, let me preface my answer by saying that age (and looks/weight) in and of itself is not the primary determinant of whether I am attracted to a woman...its what's between her ears that counts. Now, that being said, yes I have an age preference...all other things being equal, I like the hotties half my age. Why? Because they are hotties, and I'm a dirty old man.
Though as my daughter gets older, the cut off age keeps creeping up ( you 18 year olds are safe now)