its as good as the tuner
ie a remap done by an awesome tuner could make 200rwkw
a powerfc tune done by a poor tuner could make 50rwkw
its all down to the tuner, how well they tune it, and how quickly (this adds to cost)
a remap can make 500rwkw as can a powerfc as can a motec, as can a autotronic etc
no ecu is limited to a given power level, any one that says ECU XYZ will make more power, either cant tune it properly or is lying
if the car is tuned properly then there should be bugger all different in max rwkw between a well done remap and a powerfc tune
but back to your original question if it was just a basic remap ie remove speed cut and boost cut
for a typical r33 gtst it might make 170/180rwkw, with a powerfc it might make 200rwkw
again this assumptions on a basic tune and an r33, yours is a 32 so it would be different