Allthough NOTLD was quite a good movie, it simply didn't freak me out the way Alien did. So much more suspense, darkness and unexpected things, combined with superb visual effects: excellent! I loved the whole sober, clean, spacecraft atmosphere of it.
NOTLD featured zombies which is off course a great pro, but there was less suspense and more bickering between the people in the cabin. Also the characters where a bit bland and they didn't really develop in unexpected ways (apart from becoming brain-eating zombies that is
).