Why not just use Debian testing? After Ubuntu made Unity the default I switched to Debian and was pretty happy with it. AFAIK that's what becomes Ubuntu every 6 months anyway. The biggest Canonical contribution to Linux community has always been fonts, so I just copied all my fontconfig and Ubuntu fonts to my Debian install.
But then Gnome3 happened. And it was far worse than Unity - it killed virtual desktops. XFCE and KDE are not my cups of tea either, so I tried the latest Unity again and was surprised that they've fixed the most obvious issues. So I'm back on Ubuntu for now.
But you get a list of all apps via Alt-Tab. There is no isolation, so I end up with OSX-like mess of apps. Each desktop must have its own list of apps.
I submitted that as a bug to Gnome bugzilla and they told me that's "by design". I later found a 3rd party shell extension to fix it, but it was ugly as hell and kept breaking after each version bump. So I gave up. Besides, I do not want to rely on 3rd party extensions for core functionality, like switching between applications.
There is a 2nd reason why their dynamic workspaces cannot be used as a replacement for proper virtual desktops: the desktop numbers (index) keep changing: if I have desktops #1, #2 and #3 (and I use shortcuts for them, like Win+1, Win+2, etc), and I close the last window in desktop #2, Gnome3 immediately kills #3 and moves all its windows to #2. That's insane. It won't allow me to have an empty desktop in the middle.
But then Gnome3 happened. And it was far worse than Unity - it killed virtual desktops. XFCE and KDE are not my cups of tea either, so I tried the latest Unity again and was surprised that they've fixed the most obvious issues. So I'm back on Ubuntu for now.