I've got one, love it. Much smoother than any other 40 I've ever shot. The USP was designed around the 40 as opposed to a 9mm upscaled to accommodate the larger round. I've never had a problem from it, eats anything I feed it. I just got an Insight Technology UTL for it. Doesn't add much weight and I think it gives the gun a good look. Any weight it does add helps with muzzle flip imo. Great gun!