Saw this earlier today, and I was not disappointed.
The opening of the movie is gorgeous, the visuals, the score, the cinematograpy; it all took my breath away. This was not the only scene with stunning visuals as well. The scenes including holographic imagery were superbly done, as well as the scenes with the alien ship.
The plot is believeable, and I love that their attempt to answer a question about 'life' only leads to more and not really an answer. I think that there's something really fitting about this; in science there must always be a question. Without that, where is the purpose of inquiry?
I do agree that there was a certain degree of vagueness surrounding events in the film (whatever happened to the biologist? We only see Fifield after the attack), but I get the feeling that that is meant to lead into a sequel, and with that I can live with some of it. There are still questions, but they don't bug me like other questions in other films have.
There were some great twists as well in this; I still love the ending for that little moment after Shaw has left (and her final log entry was really moving from a scientific perspective).
And lastly, one line that I do not think I will ever forget: "A king has his reign, and then he dies." - there's something absolutely bone-chilling about that.
This is a great sci-fi tale that leaves some things open to speculation, others to imagination. There are some answers that I do want, but I am content to wait for sequels. To me this is great science fiction: asking questions and never stop asking them. I thoroughly enjoyed this.