LBS has both of these bikes in stock and I'm really thinking about buying one of them. 4300 is like $330 and 4500 is about $420 if I remember right. Anyone out there riding either/both of these bikes? Is the 4500 worth the extra hundred bucks or is the 4300 practically as good? Just looking for some opinons here to help me make up my mind. Will probably just be used for some mild trails and dirt road riding. Not gonna be racing it or anything like that. Thanks!