Funny, I was just in the middle of upgrading ("downloading packages") when I came across this article, and chickened out! But then I read some of the comments, and got curious, so I went through with it.
I love it! My old Toshiba Satellite feels new again. I like everything - the new software utilities (disk checker, etc), the wallpapers (how classy!), that compiz just works out of the box again (how I missed it!)...
The sound server is far better! It doesn't take full control of the computer's resources when the volume's turned up all the way (as much) anymore, and it actually sounds a lot better. (Louder, too.)
The only problem I had was that, instead of having ubuntu-desktop and ubuntu artwork, it changed it all to xubuntu - usplash, gdm, everything. I had to manually reinstall the ubuntu-themed packages. But that's no big deal.
I'm very happy I upgraded, article notwithstanding.