I've just finished the book. Fascinating.
It is basically advocating a very hardcore low carb diet with very tight blood glucose controls and medication closely tailored to the individual.
As a type 2, I didn't feel the book was weighted/aimed disproportionately at type 1s, although there was a lot of info about medication that I don't (yet) need. Although I thought his Law Of Small Numbers was delightfully sensible. And I profoundly respect the man's discipline, curiosity and dedicated endurance.
He also advocates a tough, strenuous exercise regime.
The diet advice was very basic, very strict, and a small part of the book (mainly because it was so low carb).
My gut feeling is that hitting Berstein's diet running would be a recipe for disaster. Most people will fall off the wagon very quickly. He makes frankly silly comments suggesting people should dramatically cut their food intake, try it for 2 weeks and if they are too hungry, then make an appt to discuss diet changes with their physician before adding in extra foods.
Meanwhile, back in the real world, most human beings would have been unable to endure the extreme diet reduction, and fallen head first into cream cakes by day 4. He acknowledges carb cravings in overweight type 2s, and gives techniques to cope, but I don't feel that he actually empathises with their severity.
If you tend towards extreme diets, like the Newcastle, then Berstein's is for you - but if that's the case, you are probably already counting your calories while quaffing diet shakes already.
Me? I think it was an interesting read, but easing more gently into low carbing is more sustainable in the long run. That it certainly my experience. Others may have completely different experiences.
Mind you, testing foods and fully understanding how your body deals with the foods you put in it always has to be a good idea - and that is one of his core messages.
