How are yours holding out Holger? 
They still work perfectly, Mike. Guess I never will go for pillow balls.

Thanks again for you help.

I had the chance to talk to an Audi engineer who confirmed that the TT/Cupra
mounts are about 30 % stiffer.
ps:
It's almost the same old story as on the Mk.IV, where you could run the upper
strut mount of the Seat Cupra R on a Golf, which was also stiffer.
From what I remember some guys measured 65 instead of 50 on a durometer.
Guess it will be similar on the current platform.