You gets what you pays for with UPS
I have to take slight issue with ESR, but I'm in the UK and believe that our National Grid is in somewhat better repair than the USAian one.
Bottom line: the real cheap UPSes are junk, just as his rant says, but if you work out sensible requirements and look round a bit you'll find a UPS that meets all of ESR's criteria and does what you want it to do, though not at a rock-bottom price.
Back in September 2014, and in the face of a few power flicks that had dumped my house server (which has a soft-touch power switch - these seem specially designed to turn OFF if they see even a microsecond of mains loss). Fortunately none of these corrupted the disks, but I decided that, given the Governmental unwillingness to deal with ageing generating stations and rising power requirements (think charging electric cars and the giant whole-wall flatscreen tellies that the average consumer apparently must have) that a UPS would be a good idea, so I started to look for one.
The problem: I wanted a UPS that could support my house server (30-50 watts on average) during a power loss of 5-10 mins (most power glitches are shorter than this) plus enough time for the server to shut down cleanly once it had been told to do so by the UPS. Not what I'd consider to be exactly hard to do.
ESR was partly right: this was completely beyond the 'UPSs' sold by Amazon and friends at the time.
These couldn't run my server that long, let alone do anything else. In particular, they couldn't tell the server to shut down before it drained their batteries. This was the killer: any UPS that can't do this is just junk.
So, I widened my search.
I ended up paying 300 quid for a lowish spec Riello and got a piece of kit that does everything ESR (and myself) wants. It can run my server for up to 50 minutes. It has a UPS monitoring server process that runs under Linux and is easily configurable to do what I needed: shut down the server after a total power loss of more than 5 minutes.
The end result is that this Rielllo box comfortably exceeds ESR's requirements. It has a very nice LCD display that shows current status and gives direct manual control of it. The UPS monitoring server does everything ESR and I want and maintains a UPS event log. I have always run the UPS with the batteries in circuit. It uses a pair of 12v 7Ah SLA batteries. These are currently being reported as being in better condition than similar batteries I use in my glider and that get slung after 3-4 years when their annual test says they've lost 30% of the original capacity. The UPS's internal fans are no noiser than the server it powers, so quite suitable for domestic use.
Revised bottom line: after 3.5 years the Riello UPS is still reporting that its original batteries have plenty of capacity to do what the UPS is configured to do.