So if we can all admit that Superman isn't effected by drag when flying then why the heck does he fly all horizontal? Why not fly in a sitting position with his legs crossed?
For starters he'd have more neck movement. A lot more neck movement. What I'm trying to say is it would be easier for him to take a look around him. Plus I don't know if Supes can suffer from stiff necks but he does then MAN he MUST get stiff necks ALL THE TIME from flying all horizontal.