Personally, I think it's good to take AP classes while in high school but the tests themselves are pointless especially if you're thinking about medicine. Med schools care about GPA and MCAT. By placing out of easy classes you don't get the As in those classes and instead you're making it hard on yourself by taking higher level classes for no reason. Med schools don't give a **** about what classes you take but how you do in those classes.
I've said this multiple times ... your high school mentality is not gonna work in college and your college mentality is not gonna work in med school. It's about learning what's required of you at each stage and adapting.
ex: colleges care about what classes you take in HS that's why you take APs, med schools don't that's why there's no point in taking upper level/harder classes when you're only a freshman merely to impress them. THEY DON"T CARE!!