I really don't see a difference between HD and Blu-Ray. I have some HP movies in HD and the rest are in Blu-Ray and really they look the same to me. But that could just be me, my brother says there's a difference in clarity and brightness.
Lol Piper, how right you are! What I'm not a fan of is that they put more extras on the Blu-Ray now, so you feel you have to buy it because you want to see all those extras on there. I know why they do it, but it doesn't mean I have to like it.