Generally speaking, the AP phenomenon has been a success.
The big problem with AP now is the assumption that you need to take an AP course in high school to take the AP test. Nah, there are a bunch of AP tests where you can just walk in without taking the course and wing it having merely boned up for a month or two from study guides.
My older kid got 7 courses worth of college credit from AP testing, and if I knew then what I know now, I would have pushed him to take 2 or 3 more AP tests.
For example, he got a 5 on World History without ever taking a world history course (the night before the test we studied up on Chinese dynasties), and a 4 in Comparative Government without taking that class in high school. (He took American Government AP and got a 5 on that, so it was easy to just buy a $20 guidebook to the Comparative Government test and study up on the structure of six foreign governments.)
I think he could have passed Human Geography without too much work, so I wish he'd taken that. If your kid is interested in Art History, that sounds like something that could be passed by studying in his spare time.
The reform I would propose is that AP exams should be offered not just in May, an extremely busy time of the year, but also in September for students who study on their own over the summer. (It's not like they have summer jobs anymore.)
This won't happen, though, because the current system is a conspiracy between the College Board and the teachers to make it seem like the crucial elements in the system are not the AP tests, but the AP classes. If you let kids study on their own over summer, you'd be letting the cat out of the bag.
If you can AP out of a year's worth of introductory courses, why not enter as a sophomore and graduate in three years?
Well, there are some reasons why that might not be such a great idea. A relative aced a ton of AP exams, entered the tough U. of Illinois as a sophomore engineering major, and immediately flunked out.
The conundrum is that kids who can pick up ten or eleven courses worth of credit are likely to be attending hard schools and/or have hard majors. If you show up as an Electrical Engineering major at Cal Tech or Berkeley and enroll in all 200 level math and science courses, you'd better bring your A game.
On the other hand, if you show up as an English major at a liberal arts college, why not blow through in three years and save your parents a chunk of change? When I got to Rice having placed out of English 101 and 102, I immediately took a 300 level course on T.S. Eliot. I wasn't missing anything because, in contrast to, say, math, English is only a vaguely cumulative subject.
I spent four years in college and wound up triple majoring, which is more a sign of too much time on my hands than anything else. I can't say I really needed to stick around for that fourth year. Fortunately, the tuition at Rice in 1980 was only something like $2700 per year, and they gave me a sizable academic scholarship, so it was a low stress, idyllic year.
Still, one of the things America needs to get better at is hustling its brighter young people along to maturity faster, rather than let them dawdle endlessly in academia on daddy's dime.