I can tell you right now since I did the same treatment to a 357 sig., it handles totally differently, the grip is amazing, the pistol seems to print less and it even has holes, three in number molded into the new frame module. They are set up to install tungsten weights. They are said to mitigate recoil. I did not put them on this 9 mm since recoil is not an issue but I did on the 357 sig. and in fact noticed a difference in shooting