I had a UPS when I was contracting- bought a top of the line one. But it gave out after I left the consulting gig, and I never bothered to replace it.
I just paid for that decision, as a drive crashed in my NAS because of a power failure. It was a decently old drive, so I don't know if that contributed to the failure, but it gave no indications of failure before it happened. Thankfully, everything on there was either (a) elsewhere or (b) relatively expendable.
Now, I'm looking at getting a new UPS, and not really sure about the most reliable source these days. Does anyone run a UPS and/or have any suggestions?