Had a Perrin transmission mount and a Perrin pitch stop mount on my 04 WRX Wagon with the stock 5 speed. Helped to tighten up the aging drivetrain. There was a little extra NVH, but it wasn't bad and it was totally worth it. Just replaced the entire drivetrain, including swapping in a new STI 6 speed, and the NVH was way higher than it was before with the Perrin mounts. So I switched to an OE pitch stop mount I had laying around from a VB WRX, and threw in this transmission mount in place of the Perrin. It's a really nice balance. Much less NVH than the Perrin and only marginally more drivetrain movement.