Ventajas
End product looks good. Good effort to push the quality of the art in general. A good place to start if you are starting out.
Desventajas
Some mid-level management does funny things to their own team, to make themselves look good. The higher management know what is going on, but somehow refused to take action against these people. People considering leaving current company for One Animation should note that this company might just do massive layoff from time to time. It is a company that does not really value people as human beings, but more of an item that can be used and thrown whenever. I have seen people left stable jobs in big studios for a high position in this company to be laid-off after awhile. Good way to screw with people's life.