The Cupra and TT are two different cars, especially since I have the TDi TT with Quattro.
The TT is vastly better built than the Cupra and used better quality parts, but the spec is lower as standard and some nice features that Leons have are missing, for example even with the extra auto mirrors pack I have to manually fold the wing mirrors from within the car. Brakes aren't as good either.
Ecomony on the TT is amazing though, easily 20 mpg over the Cupra, 50 mpg achievable no
problem on a run, the Cupra would do 30 mpg on the same run and overall average is about 46 mpg.
Performance is at a slight loss over the Cupra but then again there is 70 bhp difference. The torque makes up for some of this though.