So, I bit the bullet and installed windows 8 on my desktop.
And... it's not bad. Not bad at all.
Dual monitor support is marginally better, the taskbar stretches across both monitors.
The start screen is definitely not designed for desktop use, but it does work, and I'm getting used to it. I find that I've been keeping desktop/taskbar shortcuts for my most frequently used applications, and leave icons/shortcuts for less frequently used apps in the start screen, and it's working out pretty well. I actually am starting to like it better than the old start menu.
If you
really hate the start screen, you can more or less ignore it completely after booting up, and then the OS looks and feels almost identical to win7, if slightly prettier.
Some of the 'metro' (or whatever MS wants to call it now) apps are alright, built-in netflix is pretty nice.
IE Sucks... less.But the real winner for me: Holy boot times batman.
From completely powered off to the windows login screen, it seems like it takes aproximately the same time to boot as windows 7. However, it's nearly instantaneous to go from the login screen to the desktop. Seriously, it's fast.
For $40 bucks, I'd say it's worth the upgrade for the boot time decrease alone, but I wouldn't pay full price. I like that MS is trying to standardize desktop and tablet OS/applications. iOS and android are both nice, but they're still not up to the functionality of a true destop OS, and Windows 8 is heading in that direction.
The only real downside I found was the start screen, but I've been getting used to it, and might actually start preferring it over the old start menu. The only thing that I can say that I probably won't ever
like about the new UI, is that it's more annoying to power down the PC(hover cursor in top corner of screen ->settings->power->shut down.) I think think that's because most tablets are designed to hibernate/lock rather than powering down completely.