I find that guys who are players are quite nice and respectful. They are manipulative but so are nice guys in a different way. The players I've talked to appear to be in tune with their feminine side because it makes it easier to communicate with women and have them trust them easier, which is what nice guys do. The only real difference is hotness level in my opinion, which I think then determines loyalty. I think if more nice guys were hotter then more options would open up to them and therefore they'd be players.