Pros
Surrounded by extremely smart and driven young professionals. Be prepared to work with clever, sarcastic individuals who will probably call you out on your spelling error on the whiteboard.
All different kinds of people with all different skill sets all under one roof (developers, sales people, designers, etc)
Opportunities for growth---XYZ took a chance on me and offered me an entry level position as someone with very little corporate experience. When another position opened up later on, they listened to my desire to move into another area of the company and I was awarded the position. One of the benefits for working for a company in growth mode!!!
Casual dress code (if you choose)
Dog friendly
Modern office building right on the new metro line
Great healthcare options and 401k
Free office snacks and catered lunch once a week
Cons
Lots of changes and back and forth so you better be adaptable
Stressful environment at times