I haven't read all this thread and I don't intend to plough through 50-odd pages (some of them very odd!). I teach and will continue to teach the tables, whether PADI's or another brand really doesn't matter. But mainly I teach them during a Nitrox course, not an Open Water course. I find many Open Water students are not receptive of anything that requires them to think, indoctrinated as they have been that learning to dive is instant gratification. By the time they get through to Nitrox they've re-thought that somewhat, and it's at that stage I like to teach them the basics of decompression theory, with dive tables providing a simple demonstration. Most students I teach nitrox to I have never seen before, operating as I do in a resort environment, and it is noteworthy that rarely do I come across a diver with ANY understanding of compression/decompression theory. Most by then trust absolutely in their dive computers, with not the slightest comprehension of what's going on inside the computer (or indeed their bodies). Most equally have no idea of the standard assumptions in the algorithm programmed into the computer, such as standard ascent rates, deepest dive first, etc. If they know of any of them they don't have any understanding as to why.
It seems to me that most teaching these days, and I'm not just thinking of diving here, is so that the student will learn and remember, not understand. Yet learning without understanding produces a very poorly prepared and equipped student, who is likely either to forget what he has learned or, far more seriously, to mis-remember it and not have any means of checking that his memory is correct. PADI claim to be educationalists first and foremost, yet to my mind they don't have a clue of how to teach people to understand and remember. It's all about instant gratification and instant payment.
So I will continue to use dive tables, not as an end in themselves but as a means to the end of understanding. AFTER a student has understood the tables I will spend time with whatever computer he may have, showing him how the various controls work and what the various displays mean. I'll also try to explain how different computers vary in their controls, display and conservatism. But all of this explanation is based on the understanding of the underlying theory that the tables have enabled.