I've installed the Windows 8 Preview on a VHD on my elderly laptop that runs Windows 7 moderately well, and when I boot to Win 8, I tend to stay there for long periods of time. I generally go straight to the desktop, as I am there for Visual Studio, not the apps, and there is a tangible improvement in the speed and responsiveness of the system. It's a joy to use.
The technology-world-at-large seems to have hyper-focused on Metro and is missing the point that it is a tremendously-import OS in all regards. Personally, I've only used a handful of the new features and improvements that you list, but I'm already sold on it.