Avantages
Learn something new practically every day. Great experience if you want to pursue your PE one day and actually have some solid knowledge and confidence about your work. Room for improvement so long you are motivated and dedicated to your work. Very, very laid back environment, paid vacation & sick days practically as often as you need (so long as within reason, I average about 3-4 weeks a year). No need to worry about any corporal policies or chain of command. If you finish all of your work/responsibilities for the day, feel free to work on some of your own work or personal responsibilities.
Inconvénients
Small company so don't expect a large social environment. For some people it is important to be a part of a large team, for me not so much. I can see this being a con for some.