In response to customer demand, both Dell and Fujitsu Siemens are offering a free "downgrade" to XP, as are a number of other manufacturers. In a recent poll on Silicon.com (which is a site for IT professionals, so not exactly overrun with technophobes), they asked which OS members would use if given the choice. Overwhelmingly the vote was for XP, followed by OS X.
Vista came top in PC Magazine's "disasters of 2007" charts.
I have two machines, one running XP and the other Vista. Vista is used only for testing our software for compatibility (I'm a software developer). There is no way that I would make this machine my regular workhorse, as it's frankly a slow,clunky pain the @ss.
XP service pack 3 is about to be released, and all reports are that after installation, the performance gets even better in comparison to Vista.