Mate is a good, if rather basic, desktop.. I have it on my main desktop computer, which is also my main Oolite machine, as it has dual monitors and a 512Mb graphics card. If your computer is low-spec, it will cope with Mate quite well. My Mate machine is 9 years old, and has a single-core 1.0GHz AMD Athlon processor and 2.5Gb RAM. (It also copes quite well with Oolite, but witchspace jumps cause a 15-30 second 'freeze' while the new system is generated..)
I installed the Cinnamon Desktop version of Mint on my laptop, and find myself using my laptop most of the time now, despite the slight inconvenience.. the desktop is just gorgeous, with lots of nice features. Cinnamon needs the extra power of the dual-core 1.7GHz T5300 Intel CPU. If your computer has the extra grunt, I'd suggest going with Cinnamon.
You can see a small comparison of the two desktops here
This is a recent screenshot of my Steampunk themed Cinnamon desktop.. (click on it for the full-sized version) I love that Mint15 login screens can also be themed to match, and that it supports animated login screens thanks to HTML5 support (works for Mate as well)..
Here's what my login screen looks like, courtesy of its' creator, at deviantART. The blimps, airplanes, searchlights and gears all move.. (and the clock works, of course!)
http://www.deviantart.com/art/Mechanica ... -364204145