I just put in my CP-E mount, so I wanted to offer my initial impressions.
Regarding the installation, I didn't find it too bad. The most difficult thing for me was getting the engine side to line up to install the new part. I only had a bottle jack to move the engine around, so this probably made it more difficult than it would have been with a floor jack. I ended up having to wedge the bottle jack at a slight angle (I know, not recommended) to get the engine to move horizontally a bit in addition vertically. One other hassle was that the 19mm bolts were SUPER tight on the stock mount, so I had to get a big cheater to crack them lose.
Regarding the vibration issue, I did note that there is more vibration, especially at low idle. It's not dramatic, so even if it doesn't reduce over time as some others have observed, I'll be fine with it.
As far as driving with the new mount, I really like it. I can't say the difference is huge, but I do notice that there is less lash in the shifting, and the power delivery seems more... immediate. Over all, I feel like I have a somewhat more responsive tranny.
Finally, I took a couple pics of the two mounts side by side, in case anyone was curious about the difference. One thing the pictures don't show is the weight; after handling the CP-E mount, I couldn't help but notice that the stock mount felt lighter in my hand. Unfortunately, I already had the new mount in before I thought to weigh them both.
[attachment=20320:Mount_side_by_side.jpg] [attachment=20321:Mount_si...y_side_2.jpg]
[attachment=20322:Mount_ends.jpg]
EDIT: The mount with the blue bushings is the CP-E one.