Hi Spryte, I have the book and found it beneficial, as I had a background in group-recovery and wished to fully learn self-recovery, so that my AV couldn't use "you don't fully understand AVRT and it won't work" against me.
It's a few days short of 9 months since I made my Big Plan (says my day counting Beast) and I recall making it and not feeling fully 100% sure; but it was a leap of faith in the technique and in myself. I know now with hindsight, that my unsure feelings were the Beast, injecting self-doubt through the AV (thoughts, feelings and imagery that suggests the future use of al oho. - relapse/slip).
Please post any questions which may arise, while you read the book.