My Fun factor thru it's life I replaced the drive cup's with stronger ones. Then I replaced the radio. I put a Traxxas radio in it and that was good enough. The best part of the Fun Factor for me was the engine. It was a good running engine. Easy to tune, (if it needed it at all) and a great idler. That little .16 just hummed. I went thru 8 gallons in mine before a rebuild. As for the Cen transmission? The gears are pretty tough, I went thru a engine and a half until my first gears went bad. In the speed department The Fun Factor blew away Tmaxx .15 anyday. It was a fast truck. Light and nimble. A few times all to easily I did break the body posts so I stayed away from big jumps and concentrated on the little ones. The Diff/Ring gears I never had a problem with those. Built tough. The New Nx or MT 3.0 are a stronger version of the Fun Factor with lots of other improvements. I had lots of good times with the Cen Fun Factor.