Can you really tell a difference between movies and tv shows in SD vs HD if you're only going to watch them on the iPad? I tried downloading a few to see for myself but I noticed when you buy an HD video in iTunes you also get the SD version too. Once you sync the iPad I can't tell which version I'm looking at. I guess a second question is where does it say you're watching an HD video once its been downloaded? A third question I have is can I delete the SD version from my MacBook? What's the reason for keeping it?