This posting gives a link explaining how to install Gnome Shell 3.8 on Linux Mint 14 with a PPA. The Gnome Shell 3.8 desktop is very fast and it even though the desktop seems to behave a little differently when you activate the search option; the whole experience is faster and sleeker. You will need to install all three PPA`s to get this desktop to function properly; but it is worth the upgrade. The desktop background selection dialog no longer allows you to select the desktop theme as well, but that is why you should always install the gnome-tweak-tool package to configure Gnome Shell properly. I tried out the new Totem video player on an Internet video stream of North Korean television and it was able to install extra plugins required to play the stream and then play the stream perfectly. Very good for a Linux video player.
Gnome also has an improved fallback mode; but it looks no different than the gnome-fallback mode in Gnome Shell 3.6. The main Gnome-Shell desktop is a worthy competitor on the Linux desktop; but a majority of Gnome Extensions are no longer compatible with this desktop. So if you like your extensions you will be going without. Still worth installing for the speed; and that is something that Gnome Shell 3.8 has a lot of.