I know this thread is months old but I finally decided to give Gnome 3 a go. It took some work to get all of the packages installed as they are still masked, but once I finally got that and Xorg to play nice I was able to get into gnome. I have to say that it's actually pretty nice. The hot corner works well for me and they have the same window placement options that Windows 7 has. (Bump top of screen for full screen, bump left/right side for half screen)
The bad news is that multiple monitor support isn't quite there yet. I wasn't able to setup the two monitors as independent workspaces so full screen isn't an option as it will stretch across both monitors. This also seems to break the bottom panel on my configuration so at first I didn't have a way to reopen windows that were minimized. Enter the best part about Gnome 3, gnome-shell-extensions. You can add the package to get some of the extensions, but there is also a website https://extensions.gnome.org/ which has hundreds of extensions to help customize the desktop the way you want it. It works incredibly well, just find the extension, turn it on, and it will automatically download and install it for you. I added Panel-docklet S and was able to configure a bottom panel that shows all of my open windows as well as have icons for my favorites. If you want to quickly turn on/off extensions you can use the gnome-tweak-tool.
Overall I'd say Gnome 3 is very usable once you add a couple of extensions and it's actually a bit nicer than 2 once it's customized. If anything it makes me more excited to give Windows 8 a try as there are a lot of similarities between them.