What is your experience with point buy systems?
Pretty positive, though I've been lucky and haven't played with many people prone to abuse their knowledge of such systems to create ubermenschen PCs designed to hog the spotlight or rain on everybody else's parade. Those people
are out there, though.
In many regards, games like D&D that place very strict restraints on character power capacity via mechanics such as levels and classes (both of which, in D&D, specifically spell out limits on feats, skill points, combat effectiveness, etc) are designed to discourage such unsporting play.
Point buy systems, on the other hand, are designed to be as open as possible with the (IMHO) naive assumption that all players are above being annoying, socially retarded, attention whores. That said, in point buy systems, the GM is usually allowed to arbitrarily place mechanical limits on power as he or she sees fit.
As others have suggested, what kind of system you want to use will depend largely on the people you are playing with and whether or not you can trust them to not act like jerks. Frex, I think that point buy systems provide mechanical flexibility and accommodate breadth of character concept better than class/level systems, but all of the flexibility in the world is worthless if your players exist only to abuse it.