Obviously, not every example has an issue, and I consider Glocks reliable enough generally to recommend them as an option. If yours is working for you, I don't see any reason to worry about it.
H&K's are, pretty much without dispute, probably the most out of the box reliable defensive pistol out there. And most accurate.
They are expensive, the USP has a non-standard accessory rail which limits weapon-light choices somewhat. And a lot of people don't like their triggers.
For me they are the best choice,
We (my wife and I) fixed our ejection problems with our Glocks by using a better grip. I have a 17 gen 3 and she a 26 gen 4. No modifications needed, just more practice.