Just wondering if it is something I should be thinking about. I'm coming up on 3 years and about 5000 or more miles on this thing. I can check and replace valves myself but I don't have the time, tools or know how to do a complete top end (rings, piston if needed, etc.). So I'm wondering if I need to shell out the 500 to 600 bucks to get it done or should I wait until I see smoke? What is going to be the performance benefit with a revamped top end?