I also run the S2 Pro by Thunder Tiger, and Im very happy.
Very solid buggy, besides some stupid things ive done, i havent broken anything due to a design flaw. The instructions were exact, and the fit was nice and tight.

Im getting the new TTR when it makes its debut, so im kinda partial

Dont get me wrong though, my buddy has a modded Hyper 7 and a Bergonzoni and those are also nice buggies. The Hyper 7 Pro has been raced quite a bit and hasnt had any problems... I think it all depends on the the mechanic/driver that will decide how much fun and durability you will experience with your buggy.