I've been an instructor for several training agencies over the years and have found one thing to be consistant. They ALL teach the diver to safely dive to all the recreational depths. They ALL get you into the water and promote continuing education to further your skills.
I've lived, worked in and taught scuba all over the world and can say that while I've heard the stories I've never once seen a diver refused a dive based on their certifying agency.
I've found that the differences in training agencies pertains MUCH more to the instructor in terms of allowing him/her the freedom to be a teacher and not a babysitter and/or the type of administrative support offered than anything else. For the student, the level of training they got and the enjoyment we experienced in the classes I've taught over the years in no way has ever been altered by the name of agency on the C-card.