I think dual enrollment/early admission should definitely be considered for an advanced, independant learner. AP/IB are college level type courses but are still held in the highschool environment. Too much structure and handholding for some. Attending class in a university environment opens all kinds of doors for future learning - such as meeting professors and possible mentors, and exposure to courses beyond calculus/physics/biology etc.
As a former IB student, I second this. I did much better in school once I got to college. IB was way too much work to keep up with the timelines, the testing, the external expectations (and my internal perfectionism). I fell out of it in my Senior year, did practically nothing the whole year, and still needed a semester off before I started college.
My university classes were challenging, thought provoking, and fast paced, and all had the appropriate amount of work. I finally felt like I was learning once I hit college, instead of just "working."
That's just me and the IB program I went to (graduated in '96). Your situation could be different.
