Well, I think you notice a sizeable difference going from a 30 lb bike to a madone. But you would probably notice a similar improvement with a slightly less costly bike. I have known people who have gotten better bikes to improve their speed but most of those have been from 105 to Dura Ace or something like that. I think the Madone will accelerate and corner much better than your current ride and should just feel better. It should give you a bump. And what are you waiting for? We are all on the downward slope and our active years have a limit. Getting a good bike now and enjoying it while you can makes a bunch of sense.