I'm not sure myself. Sometimes I think a young guy is perfect, he is more adaptable and not as set in his ways. But he might be immature and not ready.
As for an older guy, he usually is financially set and more mature. But I feel like guys who are older when they marry might have inflated expectations of their wives, or too much history. and if they don't have history, i'm still afraid they might have become pervs by that age. I know, this all sounds like a lose-lose-lose situation but these are just my fears, and of course, most fears are irrational.
I think it is unnatural for men to contain their natural desire for procreation too long...the question is what is 'too long'? i haven't reached any conclusion on this..just my feelings