My clutch vibrates occasionally and i do have a RJM setup. Not sure why the problem comes and goes.

 

I do not have any vibrations that I've noticed... and I've been driving stick for a DD since 1993.

 

I remember there being a vibration/rattle in the shifter at higher rpms (5K+), but nothing in the clutch pedal itself.

 

Ditto. I've had the RJM pedal for 7 years; (oem clutch and flywheel), and I've never sensed a vibration or rattle through the pedal assembly.

Every once in a while I get a strong resonance after revving hard then letting off while in a higher gear, but that's 100% something that started after replacing the transmission mount. The OEM mount was damping something that the polyurethane mount exposes. And even more of a mystery, the situation became much more rare after getting tuned.

Chasing down things like this, figuring out the location and the cause, this will drive you nuts.