I had heard bad things about it from others, so was a little dubious. I installed 12.04 on a secondary partition just to try it, thinking that I would make Cinnamon Mint my main OS. But when I used it I was shocked at how good it is. There was only a small learning curve, and I was quickly more productive than ever before. I use a grid of 9 desktops, 3x3, and the way the switcher works is better for the things I have to do than any other system I have used. It is nearly as convenient as having 9 monitors. I loved the E16 pager, but this is better.
I like Dash better than menus now. For me it's faster. I don't use HUD much. The apps I use aren't very HUD friendly. But mousing up to the top bar is not a big deal. I don't need to use those menus very often anyway. The toolbars in the apps cover most things.
There's still room for improvement, but I have a great deal of confidence that things are going to improve even more. I think Mark and the developers did really well with this. This is my full time work environment now, and I am pretty happy with it.