Have authored some notes myself, albeit the engineering side. Can appreciate how little effort goes into certain sections of a reputable suppliers learning material, nevertheless presentation is often subjective ie: some like lots of detail head-on, others like to be eased in to a subject.
Looking around at whats available at the mo - most impressed with BGS based on the excellent on-line forum, with any discrepancies discussed properly, queries answered promptly, good feedback from exams and a man with a friend in the CAA who can give guidance and advice the inevitable examination grey areas.