2011 wrx sedan, vibrating, studder like feeling when pushing/ releasing clutch pedal.
This first happened when I did a fourth gear pull on the highway to about 85ish, when I pushed the clutch to shift 5th I felt it. Read up on it finding pumping the pedal to rid it (which it does).
Now it happens more often in other gears when I drive semi aggressive. Always goes away after I pump the pedal.