I have currently only raced the X-2 conversion kit and am absolutely pleased with it and it's durability. It is so good, I haven't even put the X2 kit together yet. Few things had to be modified (as per all the recomendations from forum), but it has worked flawlessly. I dissassembled completely, after 2 races and alot of practice sessions (about 3/4 gal) and there is minimal wear on any of the parts (drive cups, all gears, all universals/dogbones). I do perform mantenance after each run, which may add to the minimal wear. I have had several major crashes learning the characteristics of the new X2 and some assistance from other racers on occassion, with no shortcommings. This car seems amazing and on par/competitive with all the local buggies in my area (Associated RC8B, Losi 2.0 and Xray 808 '09, Kyosho MP9). Looking forward to all the future races with the new X2B.