In 1993 I bought an H&K USP-40. It was one of the first ones in the US and there were not even any articles written about it at the time. The gun was designed from the around the 40 S&W cartridge. I liked the feel of it and bought it because it was a modern reliable pistol that could be carried cocked and locked. I really wanted a 9mm, but the gun was only available in 40 S&W at the time, so I bought it.
The USP-40 did not seem to have excessive recoil, especially when compared to a friend's Glock 23, which I fired one magazine through and had no desire to shoot any more. I put maybe 4000 rounds through the USP40 over the years. All of the ammo that I fired was factory ammo. It included about 600-800 rounds of Corbon, which is a bit hotter than factory .40 S&W ammo. I ran the Corbon through it in the early to mid 1990s, at a time when I did not know any better.
In 2013 I was having the tritium sights replaced on the USP-40, and the person replacing the sights noticed that the stripper-rail on the underside of the slide that cocks the hammer was pancaked a bit. He also noticed that the back of barrel hood where it impacted the slide looked a tiny bit mushed so that there was tiny edge sticking up. I posted about it on the Hkpro.com, but no one who responded experienced anything similar in their USP-40s, even with more rounds through them. I am just one data point. I tend to have more things crop up with guns than most people. I sent it to H&K and they wound up replacing the barrel and smoothing the pancaked stripper rail on the underside of the slide. I still have the gun though I have not shot it in years, and have no desire to buy anything else in 40 S&W.
Below are pictures of the underside of the slide before I sent it in the H&K and after I got it back.
And here is a picture of the old barrel hood that is a bit mushed.