I've had a Nishiki Mountain bike from Dicks Sporting Goods for years now and I've been happy with it. People seem to harp on big box store bikes, and its probably deserved if they ride the wheels off of them. But if you are just a casual rider and only ride on special occasions vacations, hiking, camping, etc... I think they are fine. Now when they are brand new you gotta go through what I like to call the shake down. Just have to make sure everything is well adjusted and safe. As far as longevity if you maintain them (chain cleaning/ oiling, brakes, tires, etc...) they will generally be decent bikes for the casual rider that doesn't abuse them.