I'm somewhere inbetween. I thought it was a pretty good movie, but wasn't really all that good as a Firefly movie. The only character that really needed to be there was River, and several of them were just window-dressing. Book and Inara were barely there at all and the rest other than Mal and Simon just had a few lines here and there. And given that Simon's plotline was tied up as much as River's, he was given relatively little screen time. Anyway, the thing that made Firefly great was the character interaction, and we got so little of that as to be nonexistant. Then again, it's hard to have character interaction when most of them are barely there. And then the other characters whose storylines were closed, too, just felt heavyhanded and pointless. I get that that's how things go sometimes, and wouldn't have been out of place in the TV show, but it didn't really seem to fit the movie.

On the other hand, I liked the plot. It was pretty good, even if it felt more like Star Trek than Firefly usually did. I think that the way they wrapped up the River storyline with it was a little abrupt. (Why did the revelation affect her in that way, for instance?) But there was some good foreshadowing with the (to us) incidental portion of that storyline that I thought worked quite well.