I went to a private screening before the release. I found it visually stunning and I thought Rapace, Fassbender, and Theron performed very well. I also took issue with what felt like sloppy writing, and I also disliked how there wasn't adequate characterization for some of the characters, and that almost nobody seemed to think before doing anything. For a bunch of scientists, you'd expect them to be a little less...dumb, I guess. I feel like the movie really could have used another 30-50 minutes to flesh out the story more...was hoping I'd get a director's cut when it hit DVD, but Ridley Scott says there won't be one.
Oh, it was very pretty and quite well acted (Fassbender might be getting award acknowledgment, since he was the most...charismatic? I'd say he was the character that the audience could feel best), but the plot left me scratching my head and noting that most of it seemed the product of idiocy.
There was one scene near the end that I found particularly annoying since it threw the fact that this is supposed to be a prequel completely out the window. But it was still a damn fine movie. A lot of the horror elements were fresh and terrifying. That being said I couldn't help but hope for Theron's character to somehow take over since I thought her character was the most interesting.