I'm not too familiar with the new BSG series, but I know a little of it's space battles, and FF outerspace sequences, like it's battles, are close in style (in fact, you can see the FF ship briefly in one BSG episode!), and they follow the rule of no sound in space.
BSG doesn't follow the 'no sounds in space' rule. Firefly does, much to its credit.
Sound is muffled, but not eliminated in BSG sequences. Sometimes I wish they just went all out and got rid of it, but I an understand the dramatic desire for sound in space. Worked to great effect in Firefly (and I was very disappointed to see it violated at the end of Serenity--I know it was explained, but said explanation didn't work for me).



), but Firefly was a favorite of mine from the very first episode, and only got better from there. Frankly, I don't see a lot of similarities between the shows, as far as characters, tone or writing go, so I see no reason for an opinion of one to affect that of the other in any way.