I overheard a somewhat new technical instructor (a couple of years as an instructor is, in this game, very much the new boy) from an agency who is, perhaps, not the first one that might spring to mind when one is searching for quality instruction (and there's the issue- quality!), discussing deco theory with his students and bullshitting heartily about the core themes of the one and only deco theory that he "knew". He was surprised to hear that there there are several competing theories, each with various underpinnings and each with +/- and each with reasons why one might choose one over another and in what circumstances that might be. Good grief- and this fellow is unleashing 'extreme' technical divers (ahem!) out into the water. Good grief.
I can only say- Train Right! If not for yourself, then for the sake of your family, friends and loved ones-please seek out QUALITY training at this level and TRAIN RIGHT!