I built a s2 for a friend yesterday. Overall, pretty decent kit and should be great for club racing. The only issue I had was that the big, thin black band that supposed to seal the diff, doesn't go on, so I left it off. Overnight, no oil leaked so I think it should be fine. The plastics are hard to screw into but manageable if you have a good set of drivers. The chassis feels nice and stiff, little slop, even the ball ends were pretty good (although hard to thread on)