Discourse, indeed! Thanks for starting this thread, Babette. I don't really have an opinion on nutrasweet etal, but as usual wish to chime in. I use nutrasweet and splenda with no problems, but tend to believe one effect of these is that when I am craving my beloved sugar and replace it with a no-call wringer that has no energy to contribute to my survival (sugar does produce energy, though it is also controversial), I simply fool myself temporarily that I'm satisfied. So the deep craving of my internal self to fill up the void and emptiness that is at the core of my universe is still there, though quiet. When it comes back, it is even stronger ... a monster that hasn't been fed in awhile.
When I do use a substitute found in, say, Crystal Lite, to quench thirst and cool down (live in Arizona where temps can also rise to 120 and have only a window a/c), I usually cut them by one-half with water, because water is a better source of hydration. But drinks with artificial sweeteners, cut by at least half, make me less sick when electrolytes go wonky than sugar sweetened drinks. Water is always best.
One more point (though no one asked and it's off the subject somewhat) is that if soldiers in 120 heat were continuously drinking caffeinated cola, whatever else it had in it, they would have been seriously dehydrated (unless they were drinking an equal or greater amount of water) and would have felt quite awful most of the time. It is hammered on in the news here every hot season: a cola or tea may cool you down, but if it has caffein in it, it ADDS to dehydration, or rather it subtracts from hydration and you have to replace it with some other liquid. This is not a real problem UNLESS you are working or playing hard in triple digit heat for a long time and not drinking water, too. You can die mistaking coke for a hydrating drink in those conditions.
Plus, it should always be remember that there is such a thing as water toxicity ... e.g., you can drink TOO MUCH WATER and that, too, can be lethal. In fact, there has recently been a sad case in the news about the prosecution of two (I shall reluctantly call them) "parents" who allegedly forced their adopted little girl to drink too much water, allegedly, and she did die.
Maybe the answer is moderation in all things and weighing all in the balance. Threads like this make for great discussion, so again, thanks! I shall get off
now as methinks I have strayed into several topics not on the original agenda.