I have 3 APC UPSs protecting everything in my room. We have excellent power around here but I would not even think of running my system without a UPS. I strongly believe in power protection. Whenever I build a system for someone I include an APC SurgeArrest standard. My policy is "No APC power protection, No warranty!"
I also don't trust any company other than APC. I had a Tripplite UPS (that I paid WAY too much for) that did a LOT more damage than good.
If you look around, you can get real good deals on APC products. I paid $170 for my Back-UPS Pro 650 (2.5 years ago). That's at least $100 cheaper than I have seen it anywhere else. I also got 2 APC Back-UPS Office 280s for $35 each. By the way, all of them were new.