wiring location for unfinished shed
To me that's a no-brainer, for several reasons. It's much better protected in the wall, and it's not in the way of shelving, cabinets, wall surfacing, etc.
The NEC requires that all cabling be out of harm's way. Most interpretations prohibit surface-mounting of wiring for that reason. I prefer to run cables through the rafters (over the wall), and then through the top plate(s) and down the side of a stud.