Got a spec stage 2, quaife, and lightened svt flywheel installed around this time last year.
Clutch - very smooth, but bites really good. Still fine after about 20k miles
Quaife - definitley better handling while driving agressively. Worth it for the performance, but driveability is pretty much the same. Definitley helps in the snow though.
Flywheel - Again, nothing much different from stock, but 1st gear goes by way fast now. Also, don't have to downshift as much on the highway, when passing and stuff.
All the mods were worth the money. Especially because they didn't make the car any harder to drive...but you still get the performance.
