I don't think most older guys who go out with high schoolers are intentionally manipulative. I do, however, tend to think they're often a bit socially retarded since western society pressures adults not to date high schoolers, and thus you end up with a pool of guys which contains an inordinate amount of people who are willing to ignore what other people think. That can be a sign of confidence and independence, but it can also be a sign that the guy is selfish and cares more about immediate gratification than consequences. Unfortunately, most high school girls find the guys from the latter category, since the responsible, confident guys have usually already found a nice age appropriate lady to get involved with.
Anyway, yeah, I don't think age matters nearly so much once the person is out of school and independent. I've met cute high schoolers before, but they never really show up on my radar, so to speak. There's simply too many good reasons not to go there. Much like sex, it's not necessarily immoral in and of itself, per se, but that is not enough to say it is a good idea. Any time you're not really thinking of what's in the best interest of the other person in the relationship, you're on thin ice, particularly if the relationship is sexually active.
