For handguns, and specifically for a .45 ACP handgun, the HK USP is a difficult gun to beat. For bugging in for defense, the USP is hard to go wrong with because, like the 590A1, it’s ready to go to war right out of the box as well.
The testing that HK put the USP through truly is extraordinary. It was required to fire reliably consistently at freezing cold temperatures, at extremely hot temperatures, and after being buried in snow and mud and dirt, and while having freezing rain poured over it as well. The USP even had a bullet lodged down the front of the barrel by HK, and then had it shot out.
Simply put, the USP is one of the most thoroughly tested and proven pistols ever made. It’s also a large handgun, which while a poor choice for concealment, means it is very easy to control with limited recoil. It’s also a double action single action pistol with an external frame mounted safety and decocking lever, and holds 12 rounds of .45 in the magazine.