I typically have Chromium, a urxvt running tmux with 5-15 "windows" (a couple of which go to remote machines), two workspaces of Emacs, and half a dozen open pdfs of journal articles that I may be looking back at. When debugging parallel jobs, I may have a few more tmux instances. I find that Xmonad offers the most efficient window management in this scenario. I currently run it with Gnome3 in legacy mode because all I want from Gnome is the toolbar and session management.
I don't think the debate is between xmonad and some WM. The debate is between Ubuntu's Gnome set-up before Unity and Ubuntu's set-up with Unity.
Ubuntu's Gnome set-up was never been like xmonad or even a tiling window manager and neither is Unity. It seems to me that, as far as you're concerned, Ubuntu's default set-up sucks just as much as it always has.
