Pat,
I used Red-N-Tacky for over 30 years, but only on particular high stress, high pressure, high temperature joints and gears in farm machinery. As you said, that is what it was invented for. It is not used on all bearings and joints, just certain ones. And it was also designed not to fail at very low temperatures as well as very high temperatures.
So, I was really surprised last year, when I got into O gauge trains, and found almost everyone using it on the little gears in their engines.
But, I did as they said, and the engines seem to run fine. The grease does not drip off or deteriorate at high temperatures and seems to stay put in the gears for a long long time. (I think that this is why it is popular.)
It is a little bit stiffer during colder weather (around 55 degrees in my basement), but it only takes less than a minute or so for my engines to "warm up" and then they run fine.
So, I guess I will go with the overwhelming wisdom of the majority of the board, and stay with it. If one of my engines burns up from those cold starts in 5 or 10 years, I'll just toss it. (For me, they are just toys.)
Mannyrock
