wannaknowmom: I graduated power school in December of 06 and A school (ET like your son) in June of 06. I was class leader of both classes. I was more academically gifted than most students, I was very fortunate in that regard. But you mentioned a few things that should make him successful. I have to ask, does your son know about this board? If not, you should mention it to him, casually in an email or something. Don't direct his life, most nukes hate that. He gets enough of that from work. You said he did a lot of memorization in high school. That could be very helpful for him, his last course in A school is difficult mostly because of the mass amounts of memorization. That can also help him through the other courses as well, but conceptual understanding is also huge.
The hours will probably get to him, it gets to most people. If there is anything you can remind him to do, guide him to use his time effectively. It is much easier to maintain high enough grades to stay on 15 hours or less by working every moment you are there than to try and catch back up while you are on 25+ extra hours a week. You just can't maintain your focus when you are working over 70 hours a week.
As for the hours they work, I had a pretty cool LPO (we had a first class, not a chief) that pretty much let me run our class in A school and we had days where we worked only 3 or 4 hours. We were actually able to go off base for lunch one day and took a 5 hour lunch. In power school, it was a little more stringent as a whole. I again had the best class (grades, behavior, bearing, everything) and we got a lot of props for that. We almost always had an early Friday, along with 90 minute to two hour lunches (normally 60 minutes). There were other sections in power school that it really drove nuts because they never got extra time off.
All in all, it is going to come down to effective study habits and work ethic. Work while you are there and make it count.
Shaun