So I just got the MS3 RMM with the corksport inserts installed. So far I'm loving it, however I will say the vibes will probably be more than most of the 'mpg junkies' on this site can handle.
The car goes into gear smoother, the car takes off smoother (less the vibes) and the car shifts a hell of a lot smoother. You just feel more connected to the car.
The idle vibes aren't really noticeable... it's just during your initial clutch release things get a little shaky. I'm sure it will die down as the mount breaks in.