I've just bought a couple of those for the kids. They're pretty good, lovely looking although the shiny plastic tends to be something of a dust magnet.I was a bit dubious it being a Dell, I've always bought Vaios for home use in the past, as we used Dells at the place I used to work at and they were very plasticky feeling but the XPS models appear well made and solid to use.
I bought mine from Dell with 3Gb memory and 2x320Gb HDD Raid0 disks and it cost about £650.
Then got a couple of Dell E207WFP monitors for £170 quid each from Ebuyer.
My daughter, who's a World of Warcraft addict, reckons it's the mutts nuts..!.