Well, the it's adjustable in 2 ways - You can adjust its mounting position on the compressor housing (with the slotted actuator bracket), and you can pull apart the actuator and swap out for different rated springs. It comes set at 0.8 bar, which is around 12psi... which is the boost I want to run.
I need both those things, but I want to swap to a TF035 - if I can find one.
How does it feel shifting from 2nd to 3rd, or from one gear to any other gear while driving? First thought is check your slave cylinder is moving the clutch properly. Get someone to sit in the car (while it is off) and have them push the clutch pedal in and out. The slave cylinder should smoothly push on the clutch fork. If not, try bleeding the clutch line. If you're not losing fluid then I doubt it's leaking from the slave cylinder, might just have some air in there or the fluid is a bit old.
Could be something else like syncros or a problem with your clutch/pressure plate... but probably not.