Only issues with mine are the .45 mags. The bottoms tend to break off when doing mag changes (the mags fall to the ground then break). Used my USP .45 during an in service training and broke three mags. They were still functional just the bottom ends were broken off. Called HK about it and they sent me a large bag with replacement bottoms. I just replace them as they break.
I've also had the mag springs where out fairly quickly.
I carry my G21 for duty use.
There's nothing like the fact that you can take educated professionals with everything on the line and add a little booze and they act like juniors in HS.