<p>ED (binding form) is not meant to be a trap. It is meant to be for applicants who are committed to a given school. Obviously, if you have made an honest mistake or had a change in circumstances that affects your ability to pay, the school will not force your family into bankruptcy to get you to attend. However, if your family can afford the school, you are bound to go. If you always knew that you would go elsewhere if you got in, you should not apply ED.
I suspect ED will soon vanish as an option because so many people are abusing it.</p>