I choose CC as they have such a good reputation on the forums and the price is a bargain. I have a revo dealer located one minute away but they are charging nearly double what CC charged! Another reason was that the Revo map was very aggressive and nothing over 5500RPM. Also it had a fault where you would upload the map with your SPS box and it would be great for a day and then you could feel the power back off. The only way to get the power back was to reload the map. I have since heard that they try to use too much ignition and the Engine was backing off to save itself.
Points I miss from my TT are: Traction! Traction! Traction! Heated seats, Bose and chocolate biscuits at the stealer!
Bits that are better on the Leon: Definately faster (No 4WD losses and slightly lighter), seats are much more comfortable and supportive, Less common, a bargain in comparision and better feedback from the handling.