I had a set of spare mounts and filled all three with window weld urethane. The clunk sound on my 16 was easily heard by those near by to my car. I swapped the mounts for the filled ones. The clunk was totally gone and I tried hard to replicate it. The NVH was intense. It would be the absolute max of tolerable for DD. Mirrors, coins, glove box things, vents and still more stuff rattled. Damn, it felt so good shifting. The car was very smooth. Traction over rough road was awesome. Wheel hop in the wet and dry was obliterated.
Currently I have a filled rear mount, an insert of the passenger side and a stock drivers side. It is ok for NVH and still delivers most of the benefits that all three filled did. My wife won't let me play with her car. The difference, when driven back to back, is extreme. She hates the noise and vibes, but for me it's worth it.
Our mounts are easy to install/remove so have fun and see what works for you!