You're not missing out on too much from MATE. If anything, I found that Cinnamon had more features.
A few reasons I use MATE, though:
Freely placeable panel buttons
Proxy settings has "Manual" option, so I can use Tor as a system-wide proxy.
It doesn't run like ass on my Acer Aspire 5742z, which has 3GB of RAM.
The apps that make up the MATE desktop (e.g. Pluma, Caja, Engrampa) have all the bells and whistles. This results in a slightly cluttered-looking UI, but I like it.
It works with Compiz, so I can have my windows wobble when I move them and burst into flames when I close them, if I so wish.
MATE applications support Wayland, although they're still working on Metacity (the window manager) and a few other components, so it's not quite a Wayland desktop yet.
It's a classic. I sometimes like to install the old Ambiance and Humanity themes and pretend I'm using Ubuntu in 2009.