If I may chime into this Chat as well...
I started using unity when it came out and hated it. It was slow and buggy and had nothing I was looking for. So I switched to Gnome 3 Shell on my laptop and Desktop (with 3 monitors). I love the css customization, the plugin support, the minimalist look, and the generate workspaces as you need them. I had been running it for 2 months until about a week ago. On the laptop being a 13 inch screen (1600x900) I found window management to be somewhat of a nightmare once I opened a lot of windows at work have more than 5 open becomes and issue without a dock. The layout overview scattered the windows into the visible space and made them nearly impossible to distinguish between. On the desktop with the 3 monitors I dealt with the fact that the hot corner could only be on the far left monitor and got used to it, however, I continued to see problems with gnome 3 needing to redraw the windows and then not drawing the title bars.
So I decided to finally give unity a chance and installed the latest 12.04. I have found that as long as you use the certified proprietary drivers I have had no problems in unity not drawing correctly on the 3 monitors. I also love the fact that the launcher can exist on the middle monitor and work properly on it. Its my preference to have the middle monitor the primary one. I also noticed in 12.04 the speed of unity atleast on my machine is actually much snappier and faster than gnome 3 shell. The Unity team has really done a good job continuing to improve upon this brainchild. Now I won't say unity is perfect there is plenty to improve and still some noticeable bugs that cause usability problems (some of them regression bugs in unity 5.
, however, all the bugs I found have already been filed and most fixed for a bug update being released soon.
The other thing which I am going to argue for Unity is the Ubuntu for Android and Ubuntu for TV, getting use to this interface and then being able to utilize it through other devices and software is awesome. Consistent user experiences is what UI Developers strive for and it seems they are succeeding.
This once die-hard "gnome 3 shell" is the way to go is quickly becoming a unity fan. I however am very excited to see they continue to evolve and add competitive features. Without competition, I would probably still all be using Windows 3.1 or Dos because no one challenged the ideas. Cinnamon, Unity and Gnome 3 Shell are the big three I am guessing we are going to see continue to evolve and challenge each other to be better, and we will all use what works best for ourselves.
Without choice you get M$. Without freedom you get Apple.
Just my 2 cents...