I just completed a team kit build and it was fun. Approx 6hrs taking my sweet time. A little more complicated than a 3 diff setup with the belt drive, but I like how light and nimble the truck feels. I went with 50,000 in the front diff and 7k in rear and whoa its hooked up and turns killer still (no sway bars yet). Since I am a racer I will look into the 3rd party slipper/diff products but if you're not a serious racer that enjoys wasting money in the never ending search for speed these are not at all necessary to have fun and be competitive. So far very pleased with the truck, the build and performance and durability. I will probably buy the Losi too and have my very own "shoot out" to see which truck I think will be faster for MY driving style. I am nerdy like that