I have had a couple of Belkin units, including this one, fail to protect my equipment. Once a PC just died one day, and I found burn marks on the motherboard PSU connector. The other time with this exact unit there was a lightning strike nearby, and the computer PSU was fried along with my monitor and HiFi amplifier.
Both times I tried to claim from Belkin on their warranty. They make it very hard, and you have to send them the damaged equipment. In both cases they at first refused to pay up, but eventually I got some compensation out of them. Nothing like the value of the items though, only their "second hand" value which for Belkin means car boot sale prices.
I now have a Tripp-Lite and touch wood have no had any problems.