I don't have any major objections to the system, though I do think it's sufficiently reminiscent of Savage Worlds that you might as well just use that system, which is better supported. Certainly the playing cards wouldn't feel wholly out of place in a Firefly 'Verse game.
The GM screen for Serenity came with a large map of the ship, which is the model I use for my party's ship in my d20 Star*Drive game. It also has a large map of the Aces and Eights, which has a similar aesthetic advantage that it is a ship that incorporates the vertical dimension whereas most ship diagrams in RPGs, for practical reasons, have flat maps.
The way they present the setting does chaff me somewhat. The premise, mixing space opera with western, has a potential for hokeyness, which the TV show itself arguably does stray into, though the movie strays away from to the point of almost eliminating any hint of a western motif. But the one module put out so far -- Out in the Black -- it is full-on robo bozo loco hokey.
There were other adventures put out for free, most of them having been used in Con demos. These are fairly tightly designed around the idea that you'd be playing the characters from the show. Now, I think that can be an interesting idea, and I'd love to see my groups' interpretations of the characters. But re-arranging the adventures to get other parties in seems problematic.
As for the economics of trade, including doing "jobs" and smuggling, it would be handy to have a well-designed system for handling that and give the party a sense of barely keeping their heads above water. But who does have such a system? The best I've found so far is Alternity. It has guidelines for ship costs, maintenence costs, the value of and laws concerning salvage, the monthly cost of lifestyle and fuel, ext. But their commodities system, though they have one, is kind of problematic. There is no rule for price fluctuation, and the relative prices are the only clue as to how the markets even work. Do you know of a system that does it better?