There are two types of training. In the obvious type of training, you take a skill that the student needs to learn, and you drill that skill until it becomes second nature. Mask clearing is the poster child for this direct training. Just as important, in my opinion at least, is the *other* type of training. Let's call it "indirect" training.One important feature of the training is to solve problems before entering the water, hence the backup masks. It always seemed to me to be more hazing than training. If it was for zero viz training then all team members should be maskless. I'm not trying to argue, I just don't believe in practicing for situations that should never occur. Otherwise, you should also practice losing fins. I've seen this happen a couple of times, but never saw anyone lose a mask underwater.
In indirect training, you contrive exercises that may have no direct relevance to any particular situation you should ever encounter in diving, and you use those exercises to work on less concrete aspects of diving skill. A NAUI DM candidate has to do buddy-breathing while swimming along underwater, with half the exercise done maskless. This is *not* because there's any likelihood of needing to share a single regulator with a highly-trained buddy while swimming horizontally underwater with no mask for several minutes -- you'd have executed an ascent *well* before you got to that point. Rather, the exercise is there for other reasons: it places you in a more stressful situation to show how you respond, and it requires you to execute to a skill level in excess of what you would expect even in a problem situation.
Although I have not taken Fundies or Essentials, from the many posts from those who have I can infer that there is a great deal of both types of training in those classes. There is obviously the direct training of having to learn and execute the skills with grace and precision. Forcing you to perform to exceptional standards (relative to what is needed on a "normal" dive) or throwing a few flaming torches in while you're juggling the bowling pins is less direct but every bit as valuable toward helping you forward.
I would very much like to be able to offer something like this Essentials to students I see in the classes I DM with our shop. Although our divers are complimented quite often (so we're definitely above the curve, wherever that is ), I've commented and heard our divers commenting about dives getting silted up. They don't like it, but we're not really offering any specific training to them at this point. They know they'd like diving to be better (less silt, etc), but for the most part, they haven't realized that it *can* be.
Seeing "Essentials" out there, I definitely need to look into it more to see what I can use from it to help divers here in Baton Rouge better themselves (until we get a local UTD/whatever instructor... Baton Rouge is *GREAT*, guys! [jedi]This is the house you're looking for...[/jedi]). We've already been playing around coming up with new and more effective pieces of training, and while sending individuals over to California (or getting enough interested to get someone to visit here) isn't likely, the desire is certainly there... in some, at least.