I don't like gnome for various reasons.
It takes longer to boot, yes, KDE takes even longer but XFCE is almost instant in comparison to gnome.
Design choices, both usability and configuration, its a nonsensical nightmare.
Gnome shell needs 3d accel, gnome "classic" is constrained to the extreme and highly deprecated.
To make gnome3 usable, it would take considerable time tweaking, extending, etc. Defeating the purpose of a ready made DE.
Freebsd is not missing anything without gnome3, people used to gnome2 can switch to Xfce without any fuzz, and will even find it easier to do things, since there is no stupid gconf or alike and instead you have a proper gui with options.
Cinnamon or Unity as shell replacement might solve the usability issues somewhat, but its still gnome3 behind, lots of harm there in the memory/gpu usage department.
Yesterday I tried the latest gnome-shell for the first time. Without exaggeration, it is the worst DE I have used. It is far behind all other DE's.
In case you're wondering, I use xfce myself... (In the past used KDE mostly, and I also like the latest Unity, but it needs to be polished even more).
GNOME3 restored my faith in Linux desktop. It's slick, fast, well designed, modern, functioal, has good defaults, and compared to KDE mightily is stable despite being so young project. The features and settings are not all there yet, but I like how GNOME team really thinks what they are doing unlike KDE team, which just throws random shit on it and hope it works. For example changing application icon size or removing window title when maximized takes only one line change in gnome-shell.css. One extension took care of that transition animation after pressing meta. Functionality is there, but devs haven't apparently just decided how to put it into GUI in a sane way. I like that way of doing things.
I was on brink of buying a Mac or two, but GNOME 3.2 gave second thoughts. Right now I think GNOME3 > OS X > Windows 8 > Windows 7 > GNOME2 > XFCE > LXDE > KDE.