Well, to answer the question implied by the title: the reason I took AP courses was to get away from immature people who didn't care about their classes or about getting into university or whatever. Generally, only the keen/smart people took AP, so I got to be with people who thought the same way I did.
I didn't find AP courses all that difficult, only slightly harder than the pre-AP courses I'd taken in previous years. The step from highschool to university was still a big one, even with AP, but at least AP offered some padding.
And on the topic of transferring credits: I scored 4, 4, 4, 3, and 3 in my 5 AP classes (Physics, Calc, Chem, English, English in that order), but I chose not to transfer any of the courses for university credit, rather, I took the courses again, which again gave me some cushioning coming out of highschool. I was able to take a couple courses that I had taken in a highschool context, and although they were much harder in university, I was well prepared.
So that's my take.
