This is a much more informative (but still non-technical) description of how ALEKS works than you'll find in the typical-user-facing pages.
But yes, rereading my very old thread does remind me that we've had the same feelings you're having now. I wish I could remember more about why we felt so much less positive at that stage than now - what changed? Some combination of the topics getting "bigger" and DS's maturity increasing.
A suggestion I got in that thread, which I didn't actually use but thought was brilliant, was to do the assessments myself "as" DS. You might want to do that: next time it give an automatic assessment, instead of cancelling it, do it yourself based on what you know your DS can do. (Maybe have him standing there telling you whether he could do a question, and then do it yourself rather than making him do it - it would be quicker and easier for him, and if he's anything like my DS it would tickle him! If you're good at identifying the questions that are on stuff that's he's not already done in ALEKS, you could hand over to him for those questions only.)
