Pros
Tons of energy, very smart and friendly people, incredible food program. The founders are good guys, well-meaning, even if their lack of experience comes through (which it does frequently). For a Silicon Valley company, Airbnb is about as diverse as you'll find, which is a huge plus. Very mission driven, but often in a naively optimistic way.
Cons
No understanding of work-life balance - just zilch. This causes burnout and selects for the young, energetic, and naive. The company really needs wisdom and experience in leadership, particularly right now during this period of fast growth, but it's currently loaded with yes-men that won't say no to the founders. In fact no one says no to the founders, even when their ideas are laughable. Employees are highly expendable - like family one minute, being shown the door the next.