Okay, since we're on the subject (kind of), here's how I feel about Resurrection:
It was a half-decent episode of "Firefly."
I have no inside info about how much of Whedon's script survived the production process intact. But the line between Resurrection's motley crew and the gang from his later TV work is pretty straight, seems to me.
I have this theory. Any movie with either Dan Hedaya or Abe Vigoda in it cannot, by definition, be a bad movie. ("Joe vs. the Volcano," therefore, is a masterpiece of postwar cinema, and I'll tolerate no dissent on that point.) Alien Resurrection has Dan Hedaya in it, and he is marvelous, and he gives us the series' most fundamentally fucked-up-creepy moment. Yes, I'm referring to where he reaches up, pulls out a still-warm piece of his own brain and stoically contemplates it. I still have nightmares, man.
So by the Hedaya-Vigoda Law, Alien Resurrection cannot be a bad movie. But it's not a good movie either. Because it's not really about anything. There are some guys, and a weirdo half-breed chick who plays basketball very well and has emo nailpolish, and a gratuitous thong shot, and some aliens, and … well, that's really about it. It's got clever moments, but no actual theme to speak of, which is what makes it different from the other three movies in the series.
So above-average monster movie, really appallingly awful "Alien" movie.