I'll have to disagree with you, then. I thought the SFX were top notch, the grand entrance of the alien is beautiful (are we talking about the chestburster or the adult?), the alien scenes did not feel rushed to me, it was supposed to be an action packed way to end the movie plus it built up to the alien's entrance, it's not like it just appeared out of nowhere. And the "dangling-on-the-end-of-a-wire-and-fighting-off-an-alien sequence" is cool, something different that we haven't seen before.