AoPS is in a different category. It's my understanding that lots of kids were exposed to some algebra before participating in AoPS classes. Feel free to correct me if I am wrong.

I too plan on having DS7 take AoPS classes at some point or using their textbooks and teaching him myself but I think he could benefit from a regular algebra class first. I may change my mind half a year from now but that's the plan right now. Either way I need to have one more look at the AoPS books.

LMom