As stated in the product details, this UPS works perfectly with Active PFC power supplies. I have no issues powering my Dell Studio XPS 9100 desktop when this UPS is running off of its battery.
Managing the behaviour of your computer when connected to this UPS is very nice. If you are running Windows 7, you can either use the supplied manufacturer software, or the power management functionality built right in to Windows 7.
I've always been a fan of UPS's from APC, but CyberPower has done a great job that making a UPS that works with Active PFC power supplies that the average consumer can afford.