Pros
Open office layout allows for great communication between co-workers, making it easy to know where everyone is on a particular project, or even just for pleasant chatter during dull quiet moments. Owner is a genuine individual, of whom I developed a great relationship with over several years.
Cons
Depending on your position, compensation may not be at par with other related positions currently available. Not a whole lot of positive reenforcement or "kudos". Limited growth opportunity (both position and/or compensation). Unfortunately, I never received a raise I didn't ask/"fight" for. You have to have faith you're appreciated here, your salary/benefits will not increase unless you bring forth the issue, and lack of positive compliments leave you feeling a bit under appreciated at times.