This is amazing.... I can't believe so much of this was supposed to be done in OW.
Welcome to the club! I didn't have any idea how many violations occurred in my open water until I became an instructor. It is unfortunate, but common.
Do you find that "overall" one agency is better than the other, PADI vs SSI? I know all comes down to the instructor, but syllabus wise and skill-mastery wise?
I really don't wish to start a controversial discussion, but here goes. As you said, it does come down to the instructor. A good instructor from any agency is going to produce similar open water results as any other. From an instructor's point of view, I really liked how well prepared my students were from using the SSI online training. I didn't have to explain anything, I just added dive planning as I think all agencies do a poor job (my opinion). In my area, most shops that rent pools just have a 6 or 7 hours over two nights. No one does breathing from a free flowing regulator in CW#4, as that will require replacing a tank, and there goes 15 valuable minutes. Most skip the requirements of CW#5. One course I taught when I was teaching SSI, for some reason I stopped being able to equalize in the first pool session. With SSI, I was then able to change direction and focus on surface skills and then go back under the surface the next night. That saved the class for me, as pool time is expensive. I do like SSI's repeated hover skills, though it would be unnecessary if they required, instead of encouraging (AFAIK, everybody but RAID and the DIR agencies are the only ones who require it), students to be neutrally buoyant and trim the entire time.
Ironically, I found that by teaching neutral buoyancy and trim, I required less pool time, and I could spend more time teaching frog kicks.
The last word is flexibility: PADI is fairly rigid with its open water program, but in most places in the world, it doesn't matter. However, you cannot add required skills to courses and even if you don't require a new skill for certification, if something happens during that moment, you are going to find yourself under the bus. That said, I don't believe that any skills should be added to open water. If you overteach, you are going to have the same results as underteaching. Both are equally bad. Teach students neutrally buoyant and trim in any agency, and you'll get a solid new diver. SSI has a process for adding to courses, but I haven't explored it, only read about it in the standards. SDI and NAUI allow, encourage even, instructors to add reasonable requirements to their courses. Again, you have to be reasonable. There is no reason to have ditch and don skills, as if my scuba kit is on the bottom, I'm not going to free dive down to it and put it on. I'm going to get another scuba kit and fetch it. Where I like SDI as an instructor is that I can take their Advanced Buoyancy Control course and turn add a lot of skills like the DIR agencies' gatekeeper courses. This isn't radical stuff: finning techniques, maintaining depth, trim, controlled ascents/descents, sharing gas, deploying DSMBs; just fundamental diving skills that all divers should have.
I'm very curious about SNSI and RAID, as I've been hearing/seeing videos of some pretty thorough training.
I just think students need to shop around, educate themselves, talk to instructors, and choose the right instructor for them.
Not sure if I answered your question with my rambling. I hope I did.