Right now I'm running Pantheon (elementary project's DE) on one partition and i3 (tiling WM) on another, and neither quite seem to feel right -- the former likely because it's very WIP (granted I'm optimistically biased being a core developer of the project).
What specifically have you found advantageous to your workflow with XFCE? What did you miss from GNOME-Shell, and what exactly made you switch?
XFCE is lightweight and is more in line with how I think. I'm used to a taskbar, application menu, precreated workspaces and icons on the desktop. Could I use gnome-shell for everyday work? Yeah, but I would really be happy with the features above too. I just don't see why I should give up my established workflows.
Moved to Ubuntu 11.04 before giving up on Linux and even though I'm not the biggest Unity look-and-feel fan, it has most of the aspects of gnome-shell I like and worked smoothly on my ThinkPad T60 except for hardware volume buttons which was fixed with [1] and slow wireless due to an older kernel which was fixed with [2].
Overall this idea (inspired by Spotlight and I think perfected in Windows Vista by mapping it to a single key) of mapping the Windows key to an auto-focused, system wide search box is fantastic. I really wouldn't want to go back to a system without that keystroke. Gnome using that same structure and taking you to this nice overview/launch panel is a really slick refinement.
[1] http://forums.debian.net/viewtopic.php?f=6&t=60945#p3793... [2] http://ubuntuforums.org/showthread.php?t=1837729
Because you totally would look there and not Displays or Screen.
I'm not sure what the complaints are about it, and to me it's preposterous to say that Windows 7 is an improvement.