I stopped by fantasticplanet to talk to Cathy yesterday afternoon, and she outlined her 'meh' towards Firefly so I understand where you're coming from.

But I'm a convert to the TV show, and the movie was a continuation of the show with a continuation of the characters and set up. So, I'd recommend adoring the poster and avoiding the movie :D. (And I'm yet to be introduced to Babylon 5 but nothing compares to Battlestar Galactia, you know?)