I drove a Lambo SuperLeggera round Hampton which my fiance bought for me as a birthday present. It was amazing to drive a car like that and obviously very fast, however I didn't get to truly send it. They were saying its a driving experience not a race or whatever and so they did stop me from going full bore. Also it all goes by pretty quick!
In the end I would say its worth it to do once, to drive an amazing car if you can't drive one any other way. They often have sales too which makes it cheaper.