Steven, I guess I am dissagreeing with you.
This happens from time to time and I'm learning to deal with it, although I am flabbergasted every time. 
For one thing, the Conshelf is adequate for just about anything so if someone had a super duper fancy modern neon colored plastic regulator go TU then I think the old Conshelf would be a welcome sight indeed. The Cousteau team made thousands of dives, they used Mistral double hose regs, I bet they did not log dives either (maybe they did --who knows), my point is there are more than one solution and as good as yours is (and it is a good one) it is not the only one.
I didn't mean to impugn the Conshelf. If it's adequate for your needs, it's adequate. I thought the discussion was about whether a second-rate alternate was a wise choice. As to Jacques and his crew, I don't know if they always logged their dives but they sure kept a heck of a video journal of their doings.
Logging dives began with Padi I think, I don't do PADI, that is how I got Advanced (not Advanced OW but Advanced) and AI without logged dives.
So far as I know, logging dives began with the military, not PADI. I know that I learned to log during my NASDS OW training in 1971. As enthusiastic as you are about the old days of military-style training, I would have thought you were a log every dive kind of guy. 
SpareAir is still air and for OW it is better than nothing though I agree there are better solutions.
We agree! Better than nothing ain't much of a standard, however.
Skill training in modern Scuba classes is totally lacking, the courses taught in the 60s were the equal of most advanced and tech courses taught today--did not pass--you did not dive--did not get a C-card--so there was no reason to proove you could dive with a log book. The C-card used to mean something.
This is an ongoing subject of debate and not one that I really want to get into deeply. Let me just say that I learned to dive in the old days from an ex-Navy diver who thoroughly whomped our butts on a routine basis. Though good and honest people can differ on this, I think the training today is "good enough" (as measured by the growth in popularity of diving and the relative paucity of corpses floating around popular dive sites) and has some limited advantages over the old methods and curriculum. Sure, newby divers in the old days were better divers than newby divers today, but so what? By breaking the skills required to become an accomplished diver into discreet pieces it takes longer to become a good diver but more people are able to achieve it. A fair trade, so long as people aren't getting hurt at an unreasonable rate during the process. I will take issue with your suggestion that the old OW classes were the equal of today's technical classes - as someone with first hand experience with both, I can unequivocably say that isn't accurate.
As to yokes, yes DIN is better, a yoke is nonetheless just fine for OW diving. In caves and other overhead obstruction areas and some sorts of tech diving--DIN is far superior, OW diving the yoke is sufficient even for SOLO. After all this time I might have one knocked off next dive but then a meteor might land in my living room as well. By the way, I have both types of equipment available to me.
We agree, DIN is far superior to yoke. Where we disagree is whether or not yoke connectors are sufficient for recreational or solo diving. Meteor strikes aside, I've seen yokes knocked loose more than once in the years I've been diving and that's enough for me.
Here's what I don't get - you profess to admire the uncompromising training you got in the old days and look down on the watered-down training popular today, yet when it comes time to take one of these modern classes it appears that you also find the new-fangled training to be too uncompromising. In the venacular, wazzupwidat?
Merry Christmas.
& a Happy New Year.
