British take:
The professional soldiers felt let down by their government. They were being asked to do a job for which they were not trained and without being given adequate resources or support by their government. Nevertheless, up until Yorktown, they managed to beat pretty much all the regular armies the Rebel put up against them.
The Rebels fought a vicious guerilla war where they spent as much time killing or intimidating Tory supporters as they did fighting the British Army.
The Rebels where much better at fighting the propaganda war. Every little British mistep was overblown as a war crime, both in the colonies and the liberal ("whigs") British press, while Rebel atrocities were glossed over.
In Britain, political parties were divided. The conservative Tories who sided with the King supported the war, while the Liberal whigs/press who saw this as an opportunity to strengthen the power of Parliament opposed the War.
I read this fascinating book , "Fusiliers", a while back by a British historian who follows the story of a British regiment that fought from Lexington to Yorktown:
http://www.amazon.com/Fusiliers-Brit.../dp/0802716881
When you read it from the British point of view, there are many parallels to the American experience in Vietnam.