The title may be flame bait but hopefully this will help some fence sitters in their evaluation of Unity and Gnome Shell.
The most significant factor in my statement above is that I think the Gnome Shell developers realized there needed to be a stronger context switch between using applications and managing them. In Gnome Shell when you bring up the launcher or the desktop switcher all of the applications fall away from focus and tile in the center of the screen so that the launcher and desktop switcher can be exposed. At first I found this behavior a bit distracting and figured it was all eye candy but after a while I realized just how brilliant it was.
In Unity the context switch isn't as significant. The launcher comes into view when you need it and hides when you don't. In theory anyway. In reality it's a frustrating game of whack-o-mole. The launcher is never there when you want it and it's always in the way when you don't.
It seems the Gnome developers had a much better grasp of the basic user experience issue at hand. By design or intuition they better understood that you manage applications in a different context than you use them and there was benefit in making that separation more distinct not less.
Gnome Shell certainly has room for improvement but the amount of change required to make it great is significantly less than Unity will need.