Thanks a ton for these responses. At a minimum, we are dealing with anxiety/perfection. And the reason we asked for the eval was concern that there was another 2e source of difficulty. I think based on your answers, I'll ask for a summary of the tests being done. But generally it sounds like we aren't too far outside the norm.
One other point - we are doing shorted sessions because DS just gets fried after about an hour and a half. Tester says this is because he is working so hard on very difficult questions. I have a feeling she's saying that to be nice. But in any event, longer sessions would just be flushing money, it sounds like.
Patience is a virtue I suppose ...