Sorry for late response - I mainly post about my car
here
I now run the latest version of GC lites, and they open up the top end while sacrificing the low end compared to OEM. There is less torque below 3000rpm and more torque above 5000rpm. The response is also slightly slower than OEM, but you hardly feel it. My car is not tuned for drag racing, so it has a very flat torque curve and about 440hp - slightly faster than the M4 on chinese RON 98. On WOT the car basically pushes you back in the seat at the same rate until redline, with a slight rush towards the top end. Feels absolutely awesome as long as you keep rpms above 3000-3500.
Here's the torque projection. Look at the shape of the graph, not the absolute NM value.
https://datazap.me/u/asbjoern/bq-v22...g=1&data=22-27
Of course WG rattle is no more, and the turbo whine is almost inaudible, especially when new.
Negatives of the GC lites are mainly related to the VTT chargepipe. I have had so many issues with the clamps and silicone hoses that I could write a book about it. Due to all the track time the car sees, these items have been a constant source of boost leaks. I have installed stronger clamps, swapped silicone hoses several times, added heat shields and just purchased stiffer motor mounts to see if it will help.