Things I have noticed:
1) Age of Father - If you're older than the girl, and you're in the neighborhood of her fathers age....forget it. Never happening.
Ever. Don't waste your time. Not rational really, but it's how women think. Same applies if you're younger and going for cougar types. If she has kids near your age she will not be interested. Ever.
2) I'm getting close to 30, so almost at the point where I can be "old" to some women. Their are some girls that are VERY repulsed at the idea of dating an older guy "the ewww wtf you doing messaging/talking to me your 29 and I'm 20 types".
There is another group, feels like 25% maybe, that are very much into the idea of an older guy. They respond enthusiastically when they learn of your age or you message them online.
The last group, the majority, are generally ambivalent.
3) From what I have read and heard, large age gaps, like 25+ for an older guy/younger woman, you're going to have to play sugar daddy game. You're just not going to be attractive enough to them, even if you aged that Tom Cruise or George Clooney. If you let yourself go at all. It's over.