So sue me for some memory lapse after 3 years.

I still stand by my "slow cure" process. The "super fast" urethane does stand true when you use it as an adhesive for automotive windows like it was intended for, but not when it is layered 2" thick. The choice of method for cure time is purely a users preference.
I mentioned the vibration problems that were had with one install, because I figured it could be a problem on some cars. My car has been fine for 10K miles now with both mounts filled. I do get some extra vibration in the steering wheel and floor when the A/C kicks on while idling, but not "bad" by any means.
Chirping your tires in 2nd & 3rd is fun, especially when you can catch a streetlight race challenger off guard with it. Even with both mounts filled, I can still induce wheel hop on wet/snow covered streets, but not to the degree without them.