No experience here, but I've looked into it for my kid. Bear in mind that unless you're doing NCA (the private school option, which costs money) or independent study (which costs money), the program you'll be in is technically a public school, and you'll be bound by the public school rules. So when I asked whether we could reverse DD's grade skip and just accelerate for all core subjects, the answer was the same "no" that is our local public school's answer. But of the 3 online public school programs (other two are K12 and Calvert) in my state, it was the one I liked best.
The answers to my questions, which were asked of a national CA person, were all routed back to the local principal for answering, which leads me to believe that there are few specific answers that are both not covered on the CA website and still true nationwide.
I saw that the program touted curriculum compaction to bring struggling kids up to grade level, and asked whether that option was also available for kids working at or above grade level. The response was, "could you clarify what you mean by that." So in my state, I believe that they are not accustomed to working with PG kids.
OTOH, they offer multiple foreign languages starting in elementary (compared to 2 semesters of middle-school Spanish, which you aren't allowed to take in consecutive semesters, for our local public school). And pre-algebra in 6th / Algebra 1 in 7th, compared to Algebra 1 in 8th in our local public school.
Like one of the posters in the thread st pauli girl linked to, I have serious concerns about doing "lab" science in a virtual lab. That said, the only thing I learned in my high school lab sciences was to get someone else to do the actual hands-on work while I did the write-up.
The sample geometry lesson was far more comprehensive (both in terms of explaining multiple ways, and in requiring proofs) than what I had in high school.
If my kid had a baby in high school, I'd put her in that program rather than the local public school's (apparently very good) school for teenage mothers. If we end up getting redistricted out of our elementary (which is conveniently-located and has excellent teachers and administrators) next year, I'd seriously consider giving it a try for 5th next year. Barring either of those happening, I do not think it would be my first choice, over our local public middle school. But I would likely give it a try before we went with either of the private schools that I think have the best potential to be a good fit, and I would consider it to be a better option than an additional grade skip if boredom were an issue.
DD's current school issues are primarily social; she's quite isolated (IMHO due nearly entirely to her own unwillingness to initiate interactions even with close friends). I'd also consider CA as an option to give her a break from social issues until she's interested in figuring out how to deal with people. I don't think it's doing her any favors to get herself labeled as weird and antisocial going into middle school; that's a hard tag to shake. Whereas coming in as "the new kid" in a few years does give you more opportunity to reinvent yourself.
