Hey - I haven't read all the posts above, but I wanted to give my feedback. I now work at the system office, but was a Transfer Credit evaluator at a college for many years prior. If your student is able to take dual enrollment courses, I would highly suggest that over AP. Getting AP credit relies on getting a high enough score on the end of course test. Some colleges require a 3, some colleges require a 4. College credit, though, relies only on the grade earned in the class. If you get a C - it transfers to most schools in the USA. Some students can make great grades in AP classes, but then not do so well on the end of course test. That, basically, makes that whole semester wasted simply because they didn't earn that 3 or 4 score required. Dual Enrollment classes taken through a college are looked at just as any other college transcript.
I can't speak for other states, but in Georgia, there are 17 introductory college courses (i.e. ENGL 1101, MATH 1111, PSYC 1101, etc.) that are 100% transferrable to any school in the University System or Technical College System. As long as the school is "regionally accredited" basic courses typically transfer easily nationally. The accreditation of the school where the credit is earned is what is most important.