I have a brand new Dell Studio XPS 435- the Dell power supply could not handle the transients during a switch from house power to UPS power. Two Dell power supplies and two motherboards later, Dell could not provide any other solution - so I installed the Antec and have not had a single problem since. This is a high quality power supply that I most strongly recommend to anyone.
I've been using Antec PSU's for several years starting with the 350W to this 850W. Antec Signature Series specifically the 850W PSU is the best PSU I've owned. This PSU is extremely quite and provides the necessary power to run my computer with Nvidia 260's in SLI and the rest of my accessories with power to spare. Great PSU.