^^^ True about £300 for a ph2 172^^^
It makes a huge difference - quicker, but also changed the way it handles. Its much more responsive and the turn in is astounding - if not tail happy
I have stripped quite alot out - including unwanted stuff in the engine - aircon, etc.
The only stuff I have left is the front carpet and roof lining. [cant be arsed to take my carbon kevlar buckets out again!] plus a few other bits.
You could go on forever stripping out the car - its upto you where you stop.
Want to compare mine with yours