Had this installed at the same time I had the tranny mount installed. My mounts were in very good shape, so my cause for change was not one of failure, but to prepare for a power upgrade in my 01 Viggen, and to provide a solid foundation for the GS short-shifter, which was installed at the same time.
You will get more vibration than the stock rubber mounts - at idle during warm-up, when taking off in 1st, and when the AC is on at idle. When the car is warmed up, at idle, and with AC off, you will not notice a real difference vs. stock. It can feel like there is a large liter V8 under the hood - not necessarily a bad thing!
If you are riding in a Viggen or have modded your car to have higher horsepower, you will probably consider this a mandatory upgrade. If you are happy just cruising around comfortably, then you probably want to stick to stock mounts.
Rating: [4 of 5 Stars!]