@ThenDoctor -- I understand your apprehension and reluctance to enter into another system with custom dice... at first, I felt the same way about The Edge of the Empire/Age of Rebellion. The only thing I can say about the dice and the new SW games is that the dice mechanic used is special. I had to try the Beginner Box version to appreciate it. Please note that I am NOT encouraging you to try/play/purchase/etc.
Margaret Weis rewrote Firefly to use the standard dice sans d20, but still a narrative style game. It is using Cortex Plus w/ a slight variant of Fate (sort of). It works pretty well.
Didn't feel that you were encouraging, don't worry. I don't mind if others play the game. I'm interested in the material as any Star Wars fan is, personally I really enjoy the Sagas edition of the game, but that's neither here nor there. I simply have no wish to play it.
Saw Firefly at Gencon, haven't had the chance to play it. A buddy of mine bought it, I hope that I'll get the chance to play it after we get done with our current Pathfinder game.
I have the Firefly game in both dead tree and pdf formats. I love the system, I just can't seem to find a group wanting/willing to play it. Most folks are interested in the 'Verse, just not to actually play -- sigh. The adventures they produced for the new version are pretty good. So when you get a game started, they are worth a good look.