I went to full Avid mounts a few years ago and hated it. Any extended drive resulted in very numb hindquarters. This past winter I swapped in the OEM engine mounts, but left in the Avid roll stops. The roll stops are what hold things still when you're hammering on it; the engine mounts just hold the engine and tranny up. Most of the vibration is gone, but I still get my lightning quick shifts.

To clarify: by engine mounts I mean both the one by the timing cover and the one on the top of the tranny.