Rear motor mount is easy, just requires a couple sockets and a ratchet or breaker bar. I can't comment on the Speed6 yet, but in the MS3 it made quite a positive difference in how the car shifted and felt during heavy acceleration, increased the NVH (noise, vibration, harshness) inside the car at idle especially w/ the AC on a little bit, but nothing that was overly bothersome to me. I haven't done the other motor mounts so I'm not sure how bad those are. Everything Ive read/heard is the Diff mounts are a royal pain in the ass.