I've written about trying new desktops previously, and how much trouble I've had. I did settle into Gnome 3 nicely for a while, but my computers continued to get older and slower.
Even when I upgraded my main desktop machine, I had initially only put 4G of RAM in it, and that was barely enough to be a full-time photo workstation, so I still needed to slim down my environment, so I installed XFCE on my netbooks, VMs, and desktop/server machine.
The XFCE environment is much more familiar with plain window decorations, panels and widgets I can add and remove as I care, and a fixed number of multiple desktops which I can create and just keep available. The ability to piece together the little components is what was really missing from Gnome 3. I also like to be able to customize where my panels and widgets live. I find it more efficient to use a little space on the left and right of a wide screen for my panels instead of having them stuck to the top or bottom of the screen.
A convenient searching menu and launcher bound to a key combination is the last component I've really come to need these days. I've had it on OS X, Gnome 3, Unity, and even in Windows 7. Whisker Menu is an alternate menu widget for the XFCE panel that fills that need. Add a key binding (Alt-Space for me) to fire the show-menu command, and I'm in business!
I added lots more RAM to my main desktop machine, but I'm still going to stick with XFCE, since it feels more native to the UNIX way — stringing together a couple small programs to get a bigger job done well.