It was fun. Violent, gory fun, but still fun. It snuck in a handful of nods to the original film without beating you over the head with it, and it felt like it was meant as a stand-alone film instead of a set up for more. Enjoyable.
The predator design was pretty interesting too. Without giving anything away, it was more 'primitive' than what we've seen before – maybe because of the 300ish year difference between then and the original? Of course that would mean throwing the AvP stuff out, which is probably for the best.