I have a Cyberpower CP1500AVRLCD and it's been fine this model has been improved upon with the release of the CP1500PFCLCD . http://www.tomshardware.com/reviews/apc-smt1500-cyberpo...
The improvement is in the sinewave stepping of active PFC psu's.
No more psu buzzing when the ups kicks in.
Piece of mind for your gear and nice and affordable.