my mate has the old golf gti and he loves it but personally i dont like them.
i had the seat leon cupra my03 model and had a Revo stag1 remap and took it from 180 bhp to a rolling road printout of 205bhp.
Never had any problems major with it apart from a new starter lead to the battery, but the previous owner paid alot to hae it fixed as the oil had leaked in to the turbo some how and cost a fair whack but i owned my for just short of a year and loved the car to pieces.!!!
Cheaper than a golf gti new model and boy do they look and drive better.
Gonna be buying the cupra r version later on after my zafira gsi.