Ventajas
Being a small company, the input of all employees was greatly valued. The management was very supportive of the work/life balance and would really work with the employees difficult or "short-notice" situations. The owner of the company is very hands on and energetic about the company. He would always make time to talk with his employees and provide whatever assistance he could. The support from other employees of the company was unparalleled by other companies I've worked for.
Desventajas
Being a small company, it is more susceptible to market fluctuations (in slower times the company looked more at reducing cost than increasing revenue). The philosophy of the company changed quickly, which made it difficult to operate consistently.