One of the ways to divide I meet is break them into the "Stallers and Installers". I meet plenty of people who have installed are running Windows Vista. No OS is perfect, but those who have made the move to Vista seem to be happier there than they were with XP. The others divide into the very few who tried it and didn't like it, a few more who couldn't make it work with a specific app or device. Device support has come a long way in the last year: the present nVidia drivers work well but the initial ones were simply dreadful. With SP1 just around the corner the time is probably here for those who had a bad experience
What does surprises me is number who haven't even bothered to look at it, and the excuses I hear. I've had people whose companies have bought the right to move up to Vista telling me they're not doing it because of the cost (they're looking at the retail cost for one copy on the high street) without realizing they've paid for it. A couple of people at the BETT show last week said Vista wasn't stable, so they wouldn't try it. Monthly service packs cause my laptop to reboot about every other month; it goes into sleep or hibernate a couple of times a day but it's been an age since I initiated a reboot. Outlook and Internet explorer hardly ever close - I have 35 pages open in one instance of IE right now and 28 windows open. This workload would bring XP to it's knees. Unstable indeed !