Personally, I've used several APC Smart-UPS units (mostly 700s) and none of them have been trouble-free. I've had such problems as:
  • A unit that would claim the battery was at 100%, but if it went over to battery power, the battery capacity meter would instantly drop multiple segments (despite the fact that unit and battery were only a few months old, and the unit was not improperly loaded). Running a self-test would cause the unit to claim that everything was A-OK. It wouldn't notice that the battery charge was going away far faster than should be expected.
  • A unit (I think the same one as above, after it got a bit worse) would claim the battery was at 100%, and would pass all tests, yet if you went over to battery power, the battery would drop to 0 charge so quickly that all the equipment hooked up to the UPS would be powered off, with no chance for a clean shutdown. It would do this even if you were just doing a self-test. Really lame -- just as the UPS is designed to go over to battery power, if that's available and OK, when wall power is bad, why doesn't it go over to wall power, when that's available and OK, if the battery is bad?
  • A unit would periodically make an irksome little whistle noise, not apparently correlated with any self-tests.
  • A unit discharged a horrible chemical smell, which weirdly hung in the air, and took a long time to track down to the APC. I read later that the units sometimes incorrectly charge the batteries, heating them up and causing them to offgas like this.
  • A unit that otherwise seemed fine (and passed self-tests) and had a new battery would just flash the battery capacity LED stack on and off all the time.

It has never ceased to amaze me that APC is the industry standard, despite the constant problems I've had with them. I mean, the Matrix-UPSes my company used for the critical servers did seem to be more reliable than the Smart-UPSes (they're sold for "mission-critical" use, after all), but still...

However, last time I tried to research what competing brand I should buy, I was unable to find any enthusiastic support for the others, nor did I even get people saying, "Well, my Brand Y unit has never done anything like that."

Surely there's got to be an alternative...?