Technically it is a very good OS. It is fast and stable
First, these are some of my experiences with Windows 8, they may be atypical. Second, I'm running Office 2010 (one version old).
Windows 8 is initially very snappy, for reasons that I cannot diagnose (no high CPU usage or low amount of available memory), after I have run it for 24-48 hours it becomes slow and so I have taken to shutting it down every eventing (something I wasn't doing with Windows 7, but did do with every version of Windows prior).
These all run outside of metro, however this is suppose to be "Windows."
- Word: Crashes, if I have more than one window open.
- Outlook: Strange trouble switching between windows (often takes three clicks).
- PowerPoint: Certain slides (some that I used previously) crash Windows 8.
- SciTE (text editor): Syntax highlighting complete broken (just under Windows 8).
I've run all this by our head of IT and rather than try to fix any of it, he is trying to get us off of Windows. However at the same time we are deploying new SharePoint 2010 sites, so I do not think we are giving up on the brand.