I had a Cyberpower 2000VA that up and crapped out on me about 6 months ago. Ends up the batter finally kicked the bucket. And Cyberpower being the great company they are decided to stop offering replacement batteries on that model.
Got an APC RS 1500VA, and loving it. Gives me less power fluctuation than the Cyberpower, and the software actually works instead of locking up my machine (Cyberpower's software is pure shit). Even tells me how much juice my system is drawing in real-time.