As a recent refugee from KDE4, I've been delighted with xfce. I've only found one slight issue with the panels - how to force a panel to always lie underneath other windows?
This was apparently a configuration option at some point in the past, but I do not find it in the panel configurator.
Thanks for any hints!
If you look at "menu>>settings>>workspace settings>>margins" and set them all to zero, I think this will allow windows to cover the panel.
I checked on the margin settings and they were already at zero.
I would point out the problem (truly minor!): when a new browser window opens, it often has the close button hidden under a panel, and closure requires either dragging the window or using a right-button menu selection. Also, sliding a window about the desktop always places the window beneath the panels (except for the taskbar, where the window movement is blocked).
My experience has been that "always above" and "always below" are both options for panels as well as windows. If such a setting is not currently possible in xfce, then it would seem like a useful addition.