I bought this along with the Group N trans mount for my 2015 STI. Install involves removing the intercooler which isn't hard.
This part looks identical to the stock one but it has a harder rubber in it. I wanted to keep a stock look and stock comfort so I went with this unit over the stronger/more expensive aftermarket ones. I noticed the engine rocks slightly less and along with the trans mount the car is less jerky under hard WOT shifts at the track. I noticed no additional NVH from this product at all.

tThis in combination with the STI Group N Trans mount worked great for improving the shifting. I did also include the Whiteline positive shift kit and I certainly enjoy it. There is an increase in driveline noise but not much. This is most likely from a combination of all of these mods at once.