Anyone use Traction control?

[rvorous]

I was watching Top Gear last night, and they were testing a 650hp supercar. First portion of the test was w/ traction control on, the second half with the traction control off. When it was off, the car wasnt nearly as fast and drifted around the corners.
My question is that you see alot of autocross/roadracing cars on this site with 500+ hp. Does anyone use traction control? At what point is the horsepower overwhelming the car, and slowing you down?