The two APC SMX1500RM2U rackmount units that I had at home seemed built very well.
(Currently have two Cyberpower rackmount units, which don't need as much rack depth in my living room, but I kinda expect something industrial-sounding like AMERICAN POWER CONVERSION to be more reliable than cheesy-sounding CYBERpower. :)
I used to swear by APC but they have really gone down hill in the last decade. The first rule of a UPS should be, don't burn down the house. So when buying a new unit this year I went with the brand whose consumer PFC-compatible model didn't have several reviews about it catching fire: Cyberpower.
(Currently have two Cyberpower rackmount units, which don't need as much rack depth in my living room, but I kinda expect something industrial-sounding like AMERICAN POWER CONVERSION to be more reliable than cheesy-sounding CYBERpower. :)