My son took all the AP's in high school but at the advice of his father (EE major), my son took Calculus again as a freshman in college this year instead of testing out of it. He said it IS taught differently and that he is glad he's taking it in college as it is the foundation for the boatload of the math classes towards his ME major. But he said the AP classes in high school have definitely helped with how easy the material has been as a freshman.
Harvard's guide to what math freshmen should take is at
http://www.math.harvard.edu/pamphlets/freshmenguide.html . There are freshmen who will be prepared for multivariable calculus. My oldest son, who is gifted at math, ought to be in that category a decade from now.
Just because a college course is different from an AP one does not mean it is better. Harvard's single-variable calculus course is criticized at
http://mathematicallycorrect.com/hc.htm and the introductory textbook used has received many poor reviews on Amazon
http://www.amazon.com/Calculus-Sing...mp;ie=UTF8&qid=1327424647&sr=1-1 .
