Speedy2, they had issues with the tank and motor moutns, but have since improved those parts, so all the new kits are good. The Ofna clutch bell seems to always be just short of being the correct length, requiring spacing to avoid bound up bearings after tightening.....The only other thing I experienced any trouble with are the brake cams and the engine positioning being very close to the rear most brake rotor(user error?). I repaired the rbakes with some dremel work, which made them smooth as butta........
The X1 is a good car for the money, in fact i'd say it is easily the best equipped car for "about" $500!
But of course, it is an 1/8th scale buggy, 4 shocks, 3 diffs, 4 tires, independent suspension, 7.5 lbs, etc., etc............there is only so much that can be done differently in this class. So it's more about parts availability, durability and price.....Jim