I say if you like the bike you're riding then stick w/ it. You don't have to go out and buy an expensive bike. I rode an entry level bike for about a year and was happy w/ it but did buy a new Madone in August. Personally I can tell a difference in the two bikes but was it necessary? No. I did it because I had some extra cash and it is something I really enjoy. Really though, the bike doesn't matter...It's all in the motor!