The issue of teaching all techniques to all shooters has come up repeatedly in the thread, and I'd like to address it.
I think it is very important for an instructor to be at least passingly familiar with various alternative techniques. First, this allows an intelligent assessment and comparison against the status quo. Second, it allows the instructor to understand and integrate or fix, as appropriate, when seeing a student who has been brought up using one of these alternative systems. Third, it gives the instructor a tool in the box in the event that the status quo system won't work for a given student; e.g., a bad shoulder may necessitate a Weaver-type upper body position, people with back or knee problems may not be able to crouch, etc.
However, I cannot agree with the idea that new shooters should be shown all the possible ways to do something and then left to their own devices (and uninformed opinions) about which is "best." The whole reason someone gets instruction is to be taught, not to be left adrift to figure it all out on his own. I had some students from a huge agency a while back that teaches multiple grips to new recruits, included cup & saucer and even the old revolver grip (thumbs crossed behind the backstrap) for semiauto shooting. Then the officers-to-be just pick the one they like best. Think about that. If cup & saucer worked best for you doing your slow basic marksmanship train-up, that's the technique you'll adopt. Does anyone seriously think that makes sense?
I teach people the way I think is best. If individuals need tweaking, then tweaks are made on an individual level. But my goal isn't to show people the eighty seven different ways to reload a pistol, because eighty six of them have been proven inferior on some level. One of those eighty six might be the best option for one guy under one circumstance, and hopefully the instructor and student can realize that and address it appropriately. But it's a huge waste of the other students' time to force them to see, learn, and practice eighty six techniques that will be rejected.