Yesterday I've installed a tiny tool called Vista Inspirat. It changes the look & feel of your Microsoft Windows XP Operative System with the look of the latest Windows OS version. Cool!
The GUI is very nice and seems to me more usable. The general speed of the user interface seems faster, too. I don't know why, but the difference is sensible on my Notebook Acer Aspire 5670...
I never seen Vista before now, but with Vista Inspirat the layout results optimized and much more user friendly. I'm talking about all windows in general, the Explorer application and Internet Explorer. Also the new taskbar is very similar to the MacOs X.
Why I use MS Windows? Simply: because IMHO Windows is much more productive than Linux distributions I tested until now. Although I started using Linux since the Red Hat 5.x on my wonderful Amiga 1200 (with some expansions) 8-9 years ago, I find Windows XP the best OS for client/desktop tasks.
On the other hand I'll never try to install Microsoft Windows on a server machine. Unix/Linux OS on production Server wins to hand down.
My 0,02 €