I rarely post - but here it goes...In all reality - the instructor and to a great extent, the student define the depth and quality of the course. Training agencies provide the materials, the outline and standards (oh so needed for the legal world of the USA unfortunatley). The instructor fills in the gaps, mentors the student and expands their knowledge.
As an instructor, I'll admit the students that are most into my classes get the most out of it. They also get the most from me. I teach PADI, SDI & IANTD. My current curriculm/training material preference is PADI Online. Why? Because it is a structured progression of the basic information, then I get to focus on the tables, math, computer options, analyzers, etc...the value add. And oh yes, I am happy to take you diving & likely work on some buoyancy, but sometimes, the student lives in Northern climates and only dives on vacation, 80/80 diver. My rationale of why that is ok - at least I was able to reinforce the dive physics, safe practices and good diver etiquete under the Nitrox "quickie" class. Every chance an instructor gets to "touch" a student should be a chance to improve their knowledge and diving. That makes it a safer, better place for us all.
So training agency - it's as I say - some like coke, some like pepsi and others still drink RC. I don't care, it's all cola.