I agree with Craig. Having driven both a Cayman and a TTRS I'm sorry they're in a different league to the GTI (even with a high end remap). One's a reasonably fast family hatchback, the others are sports cars. As great as the new GTI is, it has a long way to go to match the other two for handling etc.
Personally, I'd rather save up and buy a better car than bother with a remap but that's just me. If I'd wanted a sub 6 second car I wouldn't have bought a GTI.