Windows 8, in my opinion, is good and bad. The unified interface is a good idea in theory, but not implementing this functionality across devices when this is what you're selling was a bad way to go.
Problems I've had with Windows 8:
For the fourth time, my Windows 8 install errors out when trying to use windows update with a general error. The OS is telling me there are important updates to install, but when I choose to do so, the OS fails to do so. In the past, I've referred to knowledge base articles that guided me through deleting the appropriate update log files that have become somehow corrupted.
My Windows 8 install constantly sees my 'sleeping' network printer as offline and won't wake it up.
When it does run updates, my Windows 8 install doesn't let me know when it's running automatic updates in the background so performance is severely degraded during the update but there's nothing explicitly telling me why.
When I open an Acrobat reader file from the desktop, it takes me to the metro edition.
A few times, upon login, my Windows 8 install provides me with the message that the login service is not currently running.
Updating the OS, printing to network printers, logging into a system with multiple users... These are all things we've been doing for 20 plus years in some Windows OS and they still don't work flawlessly in Windows 8.
I honestly cannot see where Windows 8 is an improvement over Windows 7. Windows 8 is the Windows ME or the Windows Vista of the modern day. It's a crap OS with a lot of good ideas that have been poorly implemented and unleashed on the public. There is currently no advantage to using this OS other than touch functionality if you want to hang out in the tablet-esque world of the metro interface.
If your primary use of a PC is shopping, playing simple games, engaging with social media channels, or simply browsing the web, just like with other tablet OS's, Windows 8 is a winner.
If productivity or development are more your speed, Windows 8 is definitely not for you and Windows 8 will provide you with a dysfunctional dual-personality OS. Even with the 8.1 update, the desktop is still bound to the metro interface in some ways.