Pros
Guaranteed you will be doing things you have never done before. Everyone there is in that boat. This can be good in terms of learning new things, but the flip side is that no one really knows what they are doing nor has the time to work it out. When the schedule is super rushed and things need to be done fast and right, and you have 5 times more things to do than you could possibly do in the given time, it can be a recipe for failure, as there isn't time to do the job well. This creates "no-win" situations. Everyone is winging it, and there are lots of mistakes and oversights as a result (and people being fired). But it may come together and be successful in the end--stranger things have happened.
Cons
All the various cons for this company stem from the insanely unrealistic schedule. They try to do design, development, qualification, infra structure, and training simultaneously in a mad dash to put something in the air. It is definitely an "I'd rather be lucky than smart" environment. The other slogan that is very applicable is " We don't have time to do it right, but we have time to do it over". But to be fair, Firefly isn't the only company in this industry afflicted that way.