<p>One more thing to keep in mind - some colleges don't let students re-take calculus 1 or 2 if they have already taken it in high school. The college my daughter is heading off to this fall says that students must head to multivariable calculus if they have either a 3+ in AB or a 4+ in BC. But they have two different multivariable calculus courses, one for students who have seen infinite series and one for students who haven't. </p>
<p>I imagine this leads to more similar backgrounds among the students who land in each course, which might make the courses easier to teach.</p>