All in all, there were very few things that I didn't like about the film. It managed to improve on many aspects of the tv series, and not simply those that would be a factor of movie. It was true that the ship looked much cooler and the special effects were better, but as far as I'm concerned, that's just the frills. What was really improved is the storytelling. For once, I didn't spend large periods of time proverbially twiddling my thumbs and waiting for something to frakking happen already. Given the strict time constraints of a movie, it looks like the writers finally picked up the damn pace.
The only thing that did sort of bother me is the whole River = Super ass-kicking nutjob and how the whole thing ended. Lets start with the super human killing machine first. I'm sorry but it's just bullshit in a lot of different ways. No matter how many skills you pump into a person, there are limits to what they can accomplish no matter what based on size and weight. I don't care if she was a quadruple blackbelt or something. I just don't see the whole reaver killing incident as being even remotely possible. It's one thing if she used her psychic abilities to make their coradid arteries explode or something, but the idea she could go all Buffy without any strength enhancement is ludicrous. Besides the whole supergirl thing has been done to death and it was an easy cop out guarenteed to get the fangirls squee'ing. I thought it was much more interesting of a concept that she might instead be a human breakthrough into psychic abilities.
As for the ending, I just don't see the Alliance stopping, ecspecially after her whole super assassin routine. It would only make her _more_ valuable to them. Not only can she gleen secrets from anyone she meets but kill them, their families, and half a city's population with nothing more than a garden rake and a butter knife? WTF? The government should be redoubling its effects to snatch her. Whatshisface might have had a change of mind, but in all those ships with all thsoe crew, I can't imagine not one person sent a report back to central command reporting on what happened. At that point, I'd imagine new orders would be sent to all the grunts to capture her at all costs and there's no way they could have had enough time to repair the ship.
So overall, it was a plus. I'm not going to miss Wash's character any (though he did finally start to grow on me a little right before he croaked) but I do regret that we never did figure out what the fuck was up with Shepard Book. He had an incredibly shitty role in the movie and then gets himself ganked without ever being able to reveal his secrets. Sorta crappy really.