Writing in SCSS lets you use features that don't exist in CSS yet like variables and nesting. The biggest feature though, in my opinion, is mixins. I'm not going to go into depth of what they are, or how they work, as there are other articles out there in the wild for that.
Some of the guys in the office recently decided they'd like to (finally) make the switch from their current text editor to Sublime Text, but unless you've been using it from the beginning, I can imagine it feels like a pretty daunting task.