I have the CP-E engine mount. Definetly the best per dollar modification.
It does NOT add horsepower or torque. But, it eliminates the CLUNK whenever you shift from first to second fast at redline. It also smoothes out the shifts, and I have not missed a shift since. It makes aggressive driving much more fun.
Although it is only a 70 durometer, it does a great job. On a more "subjective" level, I did feel more vibrations through the steering wheel and seat at idle, WITH or WITHOUT the A/C on. However, at any RPM level above idle, it smoothes right out. It does not affect the ride quality at all, no matter what durometer you get.
As for a 88 durometer, it will vibrate a bunch more. If you are sensitive to vibrations, go with stock or a 70 durometer one. I like CP-E. It is identical to the stock mount, other than the color of the rubber.
If you want an aggressive driving feel, or are tired of waiting for transmission bolts to start shearing off, get an engine mount. It doesnt really matter on manufacturer.