Good advice! I don't think most people on this forum would need to go on this program for preventing pains and injuries from having a 600+ squat, but i your story does show that if you squat a shitload of weight, going lighter isn't necessarily going ot reduce strength.
In fact it's been known for a while that lifting very heavy is not necessarily better for strength gains. 60% even works just as well, and certainly takes less toll on the CNS. Here is an article on that but I don't feel like finding the exact studies right now:
http://www.cbass.com/Carpinelli.htm
