I have one in my M&P 9mm and am impressed with it. No failures and follow up shots are quicker and more accurate. It has made double tapping a lot easier for me. And fun because I can now do it pretty effectively.
my personal experience and observations has lead me to the conclusion that if a person is getting frame battering, and excessive recoil, then they need to shoot a less powerful round, or go to a heavier recoil spring. RECOIL spring. it's function is to control the recoil and return the slide to battery for the next shot. most of the recoil devices i have seen and used in the past, are more novelty than actually working. a way of separating people from their money IMO. also the more complicated a part is, the higher the potential for another item to break or malfunction. if it's simply a range or target pistol, it just an aggravation, and not a huge deal. but what if the pistol is one a person carries for self defense? IMO, this could be bad.
these are simply my thoughts and observations. YMMV.