For my CPL bob taits book was great.
For ATPL, I knew the theory front to back, as well as Tony Wilsons front to back, AND Secombe Aviation Course Notes.
I was a bit surprised with the questions I got, must have been bad luck but virtually all the stuff I knew and had memorized was not required and I had about 15 questions on things about attitudes and really odd questions! Nothing like bob tait prac exams etc etc.
Id say read the Tony Wilson book a few times before sitting.