Elements of Mathematics: Foundations reviews?

[eternallytired]

Can anyone give me a recent review of Elements of Mathematics: Foundations?  I've seen a few people reference it recently, but the only in-depth reviews/discussions of it I can find are from 5+ years ago.  As a parent who is floundering to teach AoPS and can't afford the online classes, I am wondering if EMF is a possible alternative--still unique and challenging, but not quite as expensive as AoPS online.  ODS loves math and wants something challenging that requires creative thinking.  His greatest fear is that I'll switch him to something straightforward and math won't be fun anymore (his words).  At the same time, DH is concerned that the Institute for Mathematics and Computer Science (IMACS, the course creator) is for-profit and thus the course is not rigorous or high-quality.  There's got to be SOME middle ground between AoPS and a standard slate of courses.  Right?  Right?  *crickets*

[Roadrunner]

Cross post on Accelerated Board. I remember (at least in the past) plenty of people had experience with IMACs. I didn’t even realize their books were available without online courses. Hopefully you can get some feedback there.