How about hardware compatibility? Any chance us '10-'11 GTI owners can swap in a '12 ECU and expect everything to work?
*edit*
.....but as much as I'd like to turn it off for some hooligan fun, but I find that on the street the faster approach is to adjust my driving to get on the throttle a touch earlier to keep the rear from coming out far enough to engage the ESP. On a recent tour of the North Carolina mountains I found that the only time the ESP engaged itself was when I made a legitimate error.
So my tip is this.... if you feel that ESP is slowing you down, try getting on the throttle earlier and see if that helps. Not so much that you get on-throttle understeer, but with the right amount of forward thrust the car will track cleanly out of corners.