It certainly is coming along nicely for sure
I ran it on the live session (grabbed the daily build for March 1st in the morning, which was really the same as the beta 1 release that was put up later in the day)...
It's starting to get very stable for sure and looks superb and unity is getting nicer to work with, for sure...
I use the radiance theme also (prefer over the default theme)...and combined with the global menu (which gives you back the extra screen space when web surfing) and it's top panel, i almost feel like i am back on my old mac again (as you said, without the high price...lol)...
It's great that you can reduce the size of the unity icons and that when you have auto hide turned on (as i do) you no longer have to worry about it coming out accidentally when you go to the left size of the screen with your mouse (like when using you browser's "back" arrow key)...
Now if they would just give us the option of moving the bar to the bottom (and smaller in width of course down there)....that would be perfect
I know there is a "hack" for that...but i'd much prefer an official version...at the very least, available in the "myunity" 3rd party program...though would be even better if they offered it...