This thing is heavy, which is usually a good sign for this type of product. It does what even good UPS's don't, and that's regulate your power even when it fluctuates mildly. Sure, many products will protect you from 140V+ or turn on at 90V, but that's still enough to burn out everything from a simple wall wart power brick to a DVR from dishnetwork. I know, as I've experienced such things with my crappy Los Angeles power service. In afternoons, it'll drop to 110V, and if I use the garbage disposal, a laser printer, or turn on my stereo and 2 amplifiers, voltage drops below 108V. This is enough to destroy many sensitive products over time. It's so bad in my house, that it's destroyed two UPS's by forcing them to click on and off so much and to compensate for low voltage so much they burned out!
The APC LE1200 prevents this damage. It clicks on and returns voltage levels back to around 120V at a level high enough that your electronics don't get damage before they are protected (what's the point of protection that only helps once the damage is done?). I know it's working because I can hear it click on, and return power to the right levels even as my house voltage sits at 106-108V (confirmed by the voltage meter in my Panamax).
I'm so impressed with the performance of this unit in my home theater that I bought 2 more, one to protect my computer (it installs between the UPS and the wall to protect the computer and the UPS), and one for my plasma TV (because it's located away from my HT equipment). At $50 a piece, this thing is a no brainer. A quality UPS is 3-5x as much and still doesn't protect your equipment as well. And it can burn out. The LE1200 has little chance of burning out, so for equipment that doesn't need battery backup, or even to feed a UPS, this product is the way to go. APC LE1200 Line-R 1200VA Automatic Voltage Regulator