For a lot of younger women like myself the attention of an older guy is, if anything, certainly intriguing. The keystone to a possible relationship with an older guy of course is that you find him attractive. I don't see why a young woman would pass on a guy because of his age (within reason of course) that she found attractive both physically and intellectually. A girl in her 20's vs a guy in his 30's isn't out of the norm. Lots of successful relationships share such age gaps. I think when you start talking a wider gap in age then things get more difficult, especially as far as starting a family goes, but who's to say? You love who you love.
Speaking for myself as a woman in her early 20's if you're a late 30's guy who's healthy, works out, has a nice body, is active and wants to go out do things, hit clubs, restaurants, hang with friends, have fun, is social, intelligent, open minded, considerate, and has a good sense of humor, you're in. I don't care that you're 15 or more years older than me. There are many guys in their 40's who a very attractive and don't look anywhere near their age. I imagine the only passing grade remaining for me to consider a long term relationship is that you're good in bed. An older sexually experienced man with the stamina, energy, of a 20-year-old sounds extremely appealing to me ... that is, if I hadn't already found the perfect guy. But hypothetically, at this point in my life, I'd certainly wouldn't throw a roadblock on an older guy who met aforementioned qualities, could stay out all night dancing and partying, and then fuck me like crazy at dawn. If you're man enough for that rodeo, you're in regardless of age.