So I Bought them already and installed these light night. They make a very noticeable difference in how the car drives. The power from the car is much more responsive and smooth. It really reduced the drivetrain play, so when you press the throttle, it reduced some of the "clunk" these cars have common issues with. This difference could be seen when giving the car power and letting go of the throttle. so power transfer each way feels tighter .
Overall, much more fun.
As far as noise goes. You can feel a harsh vibration when turning the starter(no big deal). Also when the engine was idling(about 800rpm) the whole car has a pretty noisy and felt like the dash was vibrating. its not over the top noisy, but if you car is a DD or built to be comfortable I would consider it to loud. When it came to driving though, I couldn't tell any difference significantly in noise level!
I HAVE TO KEEP DRIVING ON THEM TO SEE HOW I WILL FEEL IN THE LONG RUN because I do drive my Z regularly. The vibration at idle was non existent when the engine was warming up(1,200-1,300rpm). So I will try raising my idle to 900-950rpm to see if that solves the idle vibration issue.
Some extra info:
I was running new oem mounts and they were already showing alot of wear after about six months, they were running fine for DD but disappointing for spirited driving. And Now I have a 3.0 too.
New transmission insulator
Poly transmission crossmember bushing
New oem diff mount
Poly mustache bar bushing
how's the feel after a few months?