The previous post was accurate. If we are looking for advantages that the Colonists had under the British, I would say that the sense of being part of the "parent nation" held an incredible amount of persuasion with the Colonists. The idea of being loyal to England was not something that was felt on the part of some of the Colonists. It actually carried some distinct advantages, such as knowing that they were always going to be protected by the British in the event of attack or coming under siege. Another advantage was that England represented a guaranteed trading partner that had access to other markets with control of more colonies. Yet, herein lay some of the disadvantages, in the form of being manipulated to British advantage and Colonial disadvantage. The other disadvantage was that the British held a rather static world view, in that they would continue to be the source and location of all power and control. This was in contrast to the Colonist world view, more dynamic in its conception of possessing their own autonomy and control over their political economic destinies.
The main advantages that the American colonies had was that they were part of the British Empire. This meant a great deal. It meant a lot economically. That is because in those days there was little free trade and so countries did always accept trade with other countries. Because the colonies were part of the Empire, they could trade with the richest empire on earth.
It also meant that the colonies were relatively safe. The British were arguably the strongest military nation in the world at the time and they, without question, had the strongest navy. This helped protect the colonies.
The main disadvantage was that the colonists had to obey a variety of rules that were imposed on them by the British. They had to obey British rules on trade, especially. In addition, they were not directly represented in the British Parliament and so had less political power than people in England did.