I see that I can purchase the amazon instant video in HD for $10 or the blu-ray for $20. I think the picture on amazon instant video is great, but with these types (Planet Earth, Baraka, etc.), I usually buy them on blu-ray. I know it's only $10, but is the picture much better (I am assuming the sound would be, but I don't know). My internet connection is good, so I'm fairly certain that I'll be getting the best picture possible with Amazon instant video. How is the bonus material on the blu-ray? That would probably be the deciding factor, because you do not get any extras on instant video.
bluray video is the best. this blu sometimes comes in @ 36+mbps in video, amazon instant i believe tops out at 7-8 mbps. so while amazon might have 1080p, you get less frames per second, no deep color... i must say this is the best picture quality i've seen on a blu ray. absolutely amazing. maybe rent it on netflix, buy it when it drops down to $10-15.