Under-rated, I'd say time manipulation.
No, not time travel, but manipulation. Being able to speed up, slow down, or even completely stop time around you (you being immune to the effect of-course). You could also choose to which degree other things would be affected by your power, in other words, you could move and affect other things, while the time is frozen.
Think of it, every time you are in a bad/dangerous situation, snap, freeze time and GTFO.
Every time someone attacks you, snap, freeze time and WTFPWN him.
You are feeling tired and sleepy at work, snap, freeze time, have a nap and resume.
Or in case you want to be a supper villain or something, snap, freeze time and, take, steal, move, harm or even kill whatever or whomever you want.
Or you can even speed up time, if you like.
You are suppose to meet your friend, but he just called you and told you he's gonna be half an hour late? Snap, speed up time and those 30 min, turn into 5
Possibilities are endless!
Over-rated?......hmmm I'll just go with flying like most. Aside from not having too many practical uses, it's really obvious when you use it.