I don't think it's nearly as good as the series, which was at its best when it was being relaxed and character driven rather than plot focused. But it takes the unresolved threads from the series and does at least *something* with all of them, enough that you can use your imagination to fill out the rest. It's about what I'm hoping for from the Deadwood movie.
I don't know if it was deliberate but they killed off so many characters and upended the status quo to such an extent that I didn't come out of it dying to see any more continuations. Whatever happens next would probably have to be more Star Wars than Firefly, and I don't need any more Star Wars in my life at this point.