My sister was a high school English teacher, and nothing made her happier in her career than teaching AP (advanced placement) classes. After she passed away a few years ago, I posted on two websites where the original question was about about their favorite teacher. (Both questions were specifically related to her high school)
The responses were fascinating. Every single one of them said that it was a valuable experience. A few said that they were initially resentful for the grades that they received, but it didn’t prevent them from getting into the college of their choice. Most said that it helped them prepare for college classes more than others did. A couple said that they opted not to attend college for various reasons, but they still use what they learned from her class in their lives. There was also the occasional mention of the lingering fear of red ink corrections, and I don’t blame them. I’ve not only witnessed her grading papers, but took one of her Creative Writing courses. She was liberal with the pen.
Maybe some of them were sugar-coating their responses, but considering the turnout of current and previous students at her memorial service, I doubt it.
I recommend checking on the reputation of teacher from previous students that have graduated. Not all teachers assigned to facilitate an AP class are good in that role.