So we used 80# polyurethane in the motor mounts. For the positive - throttle response is greatly improved and the car seem much more solid & tied together. There is an improvement in both handling as well as acceleration.

Now for the negative there is a bit more roughness at idle but it is perfectly acceptable. At 3/5's throttle there is more noise and vibration. Above 4000 rpm the engine begins to get a bit thrashy.

No final verdict yet. I have only had time to put a couple of miles on the car and have not taken it to redline or driven down the hwy.