Pros
You'll wear all the hats. There's actual opportunity for advancement, and you're surrounded by people who care about what they do. Nobody does the insane 90 hour crunch weeks as a habit, and that's not expected or encouraged. This isn't perk central, but as far as insurance/benefits go, you're looking at packages you'd expect from a much larger company (including the employee discount package for stuff like movie tickets/destinations, etc... that you'd get at Cisco), and there are (almost) always snacks/sandwich makings/soda in the fridge.
Cons
You'll wear all the hats. This is definitely a start-up, with all the good and bad that comes with it. If you have a skill that's not your primary function, you will most likely to be called on to use it. More transparency is always good, but in this case it's not information being intentionally hidden, it's just that there are so many balls in the air that information can take a long time to get where it needs to go, and deadlines can suddenly appear out of nowhere.