I use my mic alot.
A lot of fun socializing takes place, but I'm glad to see that mics are generally used to work as a team. I like coming onto our servers to hear mostly direction and praise to teamates.
I know it's easier to tell someone "good job" or "watch your left flank" then it is to type it out. And when you're actually talking to one another, it feels more "human" (if that makes sense at all)