[speeder]

They are very competitive track cars if set-up properly and driven well. They give the fastest 911s a good run. When Jack and Tyson won the OTC touring overall a few years ago, the toughest competition they had was from a couple of Vipers, IIRC.

That said, I'd rather walk than own one. There is a lot more to a car than lap times on a piece of paper. The overall ownership experience has to suck balls, and that's not even including being seen in it. YMMV.