It's obvious, even from what has been said in this thread, that many people had such firm pre-conceived ideas about the film, including the thought that it would be a direct prequel to ALIEN, that they felt bitterly disappointed that the film turned out to be something else and cannot stop...
I completely agree with Robert Harris. I absolutely loved everything about PROMETHEUS when I saw it theatrically and the Blu-ray is perfect. As he says, many "making of" self congratulatory documentaries are tedious in the extreme but this nearly 4 hour documentary is one of the finest examples...