Well it's really not a fair comparison, because the XPS is a 15.4" screen vs. the 17" screen of the ZD.
The Dell 9200 is a Centrino system with lots of power, the 17" screen, and a nice graphics card. However, none of these three machines will be able to use the X series video cards without a major redesign. The reason is the X series radeon uses the PCI-Express x16 bus, which isn't implemented on any of those systems yet.
However, in about 4 months, expect a Sonoma version of the 9200 with PCI-X16 and the Radeon X series.
I'm thinking of replacing my desktop with a desktop replacement and want to get either one of these. I have always have been a Dell customer but am intrigued by HP's lower cost and additional features. But am just nervous because I have never had any real problems with my dell products and am not sure about HP's reputation when it comes to performance and customer service. Any adive would be appreciated. Also am wondering if anyone has heard if either of these laptops is planning on upgrading their video cards to the Radeon X800 or X850, if not is it possible to just upgrade to this card myself?