I did one a while back, and can highly recommend it.
I had a go in an AMG C63 - well over 500bhp
It's expensive, but they really do encourage you to go flat out, and considering the rubber, petrol, wear and tear it must be good value.
They've got two circuits a very tight twisty and one more open with a bit of straight, plus the circular skid pan to demo the ABS/traction control on and off (amazing demo), then there's the emergency brake straight, with wet, and wet/dry with brake assistance on/off to demo the seat belts tightening, and the car systems taking over by braking to maximum.
Then there's the cobbly road/active suspension demo (I'd never drive my Focus that fast over road that rough, but the C63 was very impressive considering the low profiles and stiff-ish suspension.
The guy who went with me kept encouraging me to go faster, much faster than I'd imagine possible, to get so much power down and so early exiting the corner onto the main straight.
Eventually he did suggest I ease up, mainly because I was getting towards the edge of the track under power.
- I was absolutley exhausted at the end of the session!
I guess the idea is to sell cars, but there's no hard sell, not even slightly.