Went to the range and it works as advertised, recoil cut by more than half! The downside is that in an indoor range with partitions on either side, it feels like you are getting hit with an air cannon every time you fire. Kinda' cool actually, but may go back to the factory original unless practicing rapid fire. And oh yeah, it is a bit louder which is also very cool.
Bottom line, I would recommend getting one to cut down on recoil and increase the number of shots you can get on target inrapid succession. I would be careful shooting in an open area near other shooters, as was mentioned, you don't want to be too close to someone else shooting with one.