If I had a super power it would be to always be in the moment. Sometimes I forget to enjoy every day and all that the day has to offer. So if I could be in the moment then my ability would let me become more relaxed and take it all in.
If I had a superpower I would want to be able to manipulate time. To have the ability to slow down and give myself the time needed to complete tasks without feeling like I'm being rushed, and enjoy the important moments in life or work though the tough times would be life changing. Although your idea to be able to live in the moment seems much more attainable in reality.