My DYS10 was using EM in his curriculum. I think somehow that stupid spiral taught him useful math concepts, though. For instance, last year, he scored 85th percentile among 8th graders on the Explore test in math (he was in 4th), with concepts he supposedly hadn't been exposed to.
We worked with the school and he's doing an online Art of Problem Solving class this year instead of EM, and the school has agreed to let him do the homework in class during the regular EM lessons. His teacher is a former college math teacher and is thrilled to help out.
Maybe you could make a similar arrangement with AOPS or some other course? I wouldn't want to do extra drills on the basics. Seems like that would just lead to some frustration about repitition. Davidson has a good list of math programs in the data base you could search.
