I thought David, Vickers and Janek were all pretty well developed, and the dialogue between the crew with the bickering and smart remarks was sharp and familiar from the Alien Universe.
Shaw and Holloway were kind of ciphers for the typical 'idealistic scientist' characters, and the actors weren't given enough to do or define themselves within the script. Noomi Rapace is no Sigourney, but I kinda liked Holloway's wide-eyed enthusiasm.
Too many crew members with no defining characteristics lead to the usual lack of identification for the audience, but I thought Idris Elba's world weary Captain Janek was terrific and very likeable. I also though Vickers had some interesting underlying stuff going on beyond the badass beotch act.
The criticisms that the crew acted really dumb is, I think, completeley justified. They acted like B movie horror characters, Scott and Lindeloff really should have been smarter. When you get into the territory of 'the flame-thrower shouldn't have worked in that atmosphere', I really can't be doing with that kind of nit-picking. The movie had some problems, for sure, but it was leagues above the kind of drek that frquently seems to get a pass here.
Lindeloff and Scott were clearly more interested in David than any of the human characters, and I thought there was some pretty interesting underlying stuff going on with him and his motivations that could throw up some interesting discussion.
Maybe when a few more people have seen the movie who liked it as much as I did, and are willing to look past the weaknesses in the script to the good stuff (of which there was a lot, imho).
Or maybe not. Tough crowd.