I own a PS Audio Duet I use for my headphone rig. Would have never paid $250 for it new, so I found it used on Audigon. In my research, it stood alone with the filtering and protection it offered for its price point. PS Audio claims there are no voltage restrictions that other conditioners suffer from. Plus, it glows a cool blue color.
I view it as a "power conditioner" second and a over/under voltage protector first. Most surge protectors do not protect against both over/under voltage fluctuations. My parents lost a TV and a refrigerator due to a brown out (voltage drop). So, if you do invest in a UPS/power conditioner, look for over/under voltage protection.
Some of PS Audio's claims on the site are a little sensationalist (phrases like "sound/video you've never experienced before"), but the utility in some of their devices is pretty awesome, like multiple power zones that will turn on/off on a delay, "auto reboot" power zones, you can even control one UPS from your iPhone!
While I would never drop 2 grand on a power conditioning system, investing some money into power equipment and getting some free conditioning isn't bad either. I thought it was a neat little unit that was well-priced.
