I tried one of the recoil buffers a month or so ago and reported here that I had problems. For those not familiar with the product, it is a small piece of rubber/plastic that is placed in the front of the slide where the tip of the recoil spring rod protrudes. The idea is to keep the slide from impacting the frame upon recoil. The insert is a little less than 1/16th of an inch thick.
I found that I had a few failures to lock back on an empty mag and a few stove pipes. I attributed this to the slide not moving fully to the rear upon recoil. After I removed the device, no more problems.
It sounds like a good idea and fits the gun perfectly, but for me it made my firearm unreliable and thus worthless.
I advise against it for that reason alone.
Good luck and safe shooting.