mine is a t1000 29cc engine . i have replaced alot of parts, that werent broken just wanted to upgrade, put alloy parts on where i thot it needed it mainly upper areas, kept the arms plastic but have spare set of rpms for it. new radio 4pks, mine is still going strong, only issues was PS, it messed up on 2nd tank, fixed that by installing a PS with the collar on the wheel, keeps pawl from cocking that was causing the issue. IMO, or as far as my truck goes, its been fantastic and theres nothing wrong with KM's.
there is always gonna be the diehard hpi guys out there, and nothing wrong in that at all. but if strapped on cash, the KM is good choice, as money saved on it NOW, can go towards any upgrades LATER. each brand has its lemons, as you will read on all the threads on hpi and km's. and both have theyre super great ones, that are great. just get what u can afford, whether it be hpi or KM.