I have finally decided to take the plunge. Last night I upgraded my Vista desktop machine to Windows XP, and this afternoon I will be doing the same to my laptop.
You can read the whole review about the experience of upgrading from Windows Vista to Windows XP here. The review concludes with this:
To be honest there is only one conclusion to be made; Microsoft have really outdone themselves in delivering a brand new operating system that really excels in all the areas where Vista was sub-optimal. From my testing, discussions with friends and colleagues, and a review of the material out there on the web there seems to be no doubt whatsoever that that upgrade to XP is well worth the money. Microsoft can really pat themselves on the back for a job well done, delivering an operating system which is much faster and far more reliable than its predecessor. Anyone who thinks there are problems in the Microsoft Windows team need only point to this fantastic release and scoff loudly.