I upgraded namely because it was cheap. $40, put it on mine and my 2 sons PC's.
My impressions:
@wolfgrimdark is right. I have installed every version of windows and 8 is by far the fastest and easiest in my experience.
It did have a driver for everything in my system but almost every one was old. So it is still very important to check for new drivers. I had to update chipset, Nvidia, Creative, IRST, Well, basically every driver. Also do your windows updates.
I typically install my chipset driver then do all my windows updates, then install all other drivers to avoid windows over writing some of my drivers during the update process.
I assume @wolfgrimdark updated all his drivers before giving up on Skyrim and I know all systems will vary but I have no issue with Skyrim on win 8 with 97 mods running and my 2 sons, 2 brothers and a number of friends also run Skyrim without issue. So if you are thinking about getting windows 8 I wouldn't worry about it not running on wolf's computer but I wouldn't put any stock in the fact that me and some others have it running without issue. In short when it comes to specific games you'll just have to install it on your system and see what happens. This isn't meant as a negative towards your post @wolfgrimdark in anyway I appreciated your input.
I use Stardock's start 8, Fences 2, Windows FX 5 and Object Dock. It by passes the useless (for me) metro interface and makes a great Organized desktop. It also makes it nothing like windows 8 vanilla experience and could just as easily be done on Windows 7. Not sure why Microsoft didn't look at some of these desktop enhancements before making Windows 8. They make any version of windows much better imo.
As for navigation, it's very easy. The windows key plus x,d,r or c will take you pretty much anywhere you want to go. Not sure what the confusion with the power button is about. Press windows key-c ( or move the mouse to the bottom right of the screen) and the charm bar will open, select power and then choose shut down, log off or sleep.
The metro interface is very ugly imo and I haven't found a worth while app for it yet. You can use it as a giant start menu but I found that very annoying as you had to keep switching to metro then launch the program and it would send you right back to the desktop. Then repeat if you want to open multiple programs as I often do when working or modding.
I have 3 monitors so I thought it would be great put the metro interface on 1 and then quickly open my programs on the other 2. Nope, when I open a program even on a different monitor the metro interface closes, so I have to reopen it and do what I explained above.
My last 2 biggest annoyance with Metro is it likes to hijack media even though I set other programs as the default player several times and the browsers don't sync. If you have a browser running in metro and bookmark something it won't show up when you run the desktop version. ( this was the way it was at launch as I haven't used Metro in quite a while I don't know if that's fixed.)
I would say there is no major reason to get 8 if you have 7. There's some security,8 probably works better for a home server, better boot times and will be supported longer. If you do want to get it keep in mind it will be going up to $200 in feb. I believe. At that price I wouldn't recommend it to anybody but at $40 I feel it's worthwhile if you want the small benefits.
I haven't run into anything I couldn't run that I could run on windows 7. I also benchmarked skyrim on both and saw virtually no difference. Other than boot time and faster install I haven't noticed any change in speed.