I used to use an ipod 4gen but I switched to ipad. Advantage to this would be being able to see more (before the zooming existed) it was also a lot less laggy for me. The only disadvantage to this would be getting used to the controls, because bigger space. I'm finally used to it so I guess that doesn't matter.
Though ios6 made it more annoying to use because I lag out a lot more. So ya