When you look at accident analysis in cave diving from purely a training standpoint, before cave training was as easily available and promoted as it is today, the majority of training related deaths occurred to untrained divers venturing into cavern and cave environments. Today, training related fatalities are primarily happening to trained cave divers who are exceeding the limits of their certification. Whatever agency one chooses, it is very important to remain within the parameters of that training, build experience slowly and seek instruction at each level of cave diving. Also, IMHO, training with different instructors at different levels allows a student to gain other perspectives and learn different tricks of the trade and skills. Wherever you begin your training, explore various training avenues just as you explore various tunnels and cave systems to be a well-rounded cave diver. If you begin with an aggressive program or instructor, after you've been no-masked, S-drilled, valve drilled, and air gunned to death, you may want to train with a less aggressive instructor who will teach you more of the art of diving and who may focus more on geology and hydrology than on emergencies. This way you'll have the confidence in your ability to handle emergency situations, but you may also add training that will further your understanding of the environment by having the chance to see that environment and watch the beauty of your instructor in action as he or she uses line and swims. Too many failures in a class will deny this aspect of learning and not enough experience with problem and emergency management won't test a student's reaction to stress and build confidence. An instructor who can balance all of these very well is your best bet to start regardless of the agency.