I (foolishly?) decided to install it over my Windows 7 partition on my Studio XPS 1640. I haven't had much trouble with it. I'm not sure if it is because it is a laptop or that I'm just used to it, but I have ended up using the desktop about 90% of the time. I had trouble with Bluetooth for a while, but I downloaded some software from Dell's website and everything is working fine now.
The only thing I'd change would be adding the ability to have 50/50 on metro apps and 80/20 on desktop apps. I've tried to run a metro app and a desktop app side by side and it isn't possible.