Just watched this weekend as well. Really enjoyed this - as a good, low-level sci-fi flick set in one of the only genuinely newly established and iconic sci-fi movie franchises of the last decade.
Did not know what to expect at all and was pleasantly surprised, in spite of the occasional tendency to "over-Diesel" which may grate with or annoy some people. What there is of substance is a well-thought plot, decent special effects, and some great moments from a reasonably entertaining film.
Would recommend on the basis of the sci-fi premise alone, which is horrendously under-subscribed in today's comic-dominated movie world.