I've looked over
Serenity, am reading through it, have played in a demo, and will be starting a campaign in 2-3 weeks. I'm reserving final judgment until we finish the campaign, but, so far, I'm just not really impressed with the system. It feels really half-baked to me.
I also think that the GM advice and the perspective on gaming implicit in the writing of
Serenity is really atrocious. It really saddens me that, afaik, the game has sold so well to people (i.e., browncoats) for whom this may be their first RPG.
As for ignoring the rule content for the setting material, I understand what you're saying, but I don't think it's really a cost-effective option, given how little non-rule content is in there. You could buy both of the
Firefly companions for about the same price. Add that and the DVDs to your system of choice (d20, GURPS, FATE, PTA, whatever), and you've pretty much got what you need.
Sorry to threadcrap.

I've been getting ready for our campaign and have to keep resisting the urge to throw my copy of
Serenity against the wall. I love BSG, but there's no way I'm buying the RPG. If I hear lots of glowing reviews, I may take a look.
Were I to ever run a BSG game,
Burning Empires is such a good fit that I'd just use that.