I think the movie would have been better if Kate Bosworth was replaced by kate beckinsale but I was happy with kevin spacey and the guy who played superman did a good job so overall its worth a watch
I just hope it was good enough for them to make a sequel... because we have yet to see Superman face a real villian with the possible exception for Zod in Superman II.
Another debate was that the Xenomorph contained an endoskeleton as well as its hardened exoskeleton. The primary fuel for this was the Xenomorph skull seen as a trophy in the movie Predator 2[22], as well as a clearly visible spine and the fact that exoskeletons are incapable of supporting organisms of such size.