I, personally, like EPGY math. It gives a good foundation to a lot of higher maths. DS7 is currently taking the 5th grade math. Some of the geometry is pretty tough. Other things he is taking includes multiplication of higher numbers (ex: 1465*8), probability with sets, adding and subtracting mixed fractions, lowest common denominator, reducing fractions, converting English sentences to mathematical sentences (ex: Mike has more fruit than twice Jane and Amy together), and denial (ex: a+b=c the denial is a+b=not c).
That being said, once DS is finished with 7 grade math through EPGY, we will try AoPS.
Thanks Portia. Quick question: do you do open enrollment or the instructor guided course? I haven't really looked at the website too much, so I don't really know what the pros/cons are.