If I'm on a dive boat and I need to pick a buddy from a random group of people I've never met before, I'm going to pick the relaxed, laid-back, modest guy (or girl) whose equipment was obviously chosen to work well in recreational diving, over the guy who is dressed in all black, with a heavy-lift tactical BC and huge knife strapped to his leg (obviously wanting to look like a Navy SEAL) who is bragging about how deep he has gone and how much his gear cost. That holds true even if the laidback guy only has his open water and the braggert is an instructor. I hate macho divers and think they are the bane of the diving industry. Read Rodale's "Lessons for Life," it has many divers with advanced certs including instructors dying because they did something stupid out of hubris. Pride from an inflated sense of "expertise" kills more divers than trepidation caused by lack of knowledge.
That being said, I think NAUI has the best open water training. There's a reason Europeans say PADI stands for "Put Another Dollar In." And I've seen a lot of panicky SSI divers who had been diving longer than I had when I dove with them. I doubt they are still diving today.