Definately a lot faster round corners with ESP off. Even more so in the wet.
Had constant wheelspin at 70 a few weeks ago. (private road etc).
ok so it may be fractionally quicker with the ESP off when you drive the car near to its limits.
However as you have pointed out yourself with the 'constant wheelspin at 70' it can also be slower for those with lack of talent, and it is definately slower if you find yourself upside down against a tree. Or god forbid looking down on your car upside down against a tree.