Working at the range I get to see a wide variety of firearms. I also get to see a wide variety of problems and issues with firearms.
Last week I ran into one of my neighbors at the range. He was shooting a S&W pistol in .40 cal and was concerned about bulges in the brass.
When attempting to help my neighbor, he tried three brands of ammunition to find the same serious bulge in the brass. The particular pistol was destroying the brass and was creating a potentially unsafe situation by having a massive amount of the round unsupported by the chamber. I advised the owner to send it back to S&W. At that point I learned that he also owned a S&W M&P Shield which previously was dropping the mag when the pistol was fired until he sent it back and S&W fixed it.
Another less then fun issue encountered was a .22 round jammed sideways in the grip/magazine well of a S&W .22 autoloader.
A malfunction like this is a fluke, but even so was a major pain to clear. It took tool and a good bit of time to drive that unfired .22 round of the niche it got stuck in.
Had an interesting experience with a Diamondback DB9.
The owner of this pink Diamondback DB9 subcompact 9mm pistol was having all sorts of failures to feed and stovepipe issues. When watching them shoot I could tell nothing wrong with how they were shooting, and a firm grip was used. I suggested that they send the pistol in for service. After that has been decided, they asked if I wanted to shoot it, so I took them up on the offer.
The DB9 has a long trigger pull with a very long reset, being a very small light 9mm, I found it unpleasant to shoot and shot it poorly. However when I shot it, there were no malfunctions.
While a neutral grip is taught as the preferred way to shoot pistols, when you have very small pistols with very heavy trigger pulls, the crush grip can be the better choice. It has several advantages such as helping prevent limp wristing issues, helping minimize movement in fingers other then the trigger finger, help control recoil of these light weight mini-pistols, and more. If you want to learn more about the crush grip, look into Mas Ayoobs writings.