All I will say is anyone can destroy an engine in under 500 miles or get one to last many thousands...even Chinese engines. No, CFMs are not yet at the longevity level of Yamaha, Honda, Kawasaki or even Polaris or Can Am. But they are closer then they have ever been. If you are an average rider that takes care of their machine and doesn't mind little things that need replaced, then CFM may well be something you want to look at...especially the 800s. But if you are like many others out there that abuse their machines daily and practice differed maintenance, then better take CFM off your list.