Danny, it's been awhile since I read up on this stuff (I learned what I wanted and haven't really kept up). I believe that though a higher viscosity oil will create more friction, it does generally lead to lower sump temps. In your analogy, remember the difference in heat vs temperature (your honey will also need to be heated a lot longer to reach the same temp as the water is).
Like I said, even M1 15W-50 has an excellent pour point (about -40*F IIRC). It 'pours' as well as the 10-40 dinos I use. I do feel that I get pressure a little faster (a highly subjective observation on my behalf) with the 15-50 than dino 10-40. I feel the operating pressure of syn 15-50 is on par with dino 10-40 (and a little lower than dino 20-50).
We should note that I see ambient temps of nearly 120*F in the summer (we wont talk about the temps of the air rippling off the asphalt). When I was remarking about protection (as an absolute), it was with that in mind. When you hit the AutoX track around here (for instance) in the summer, most everyone runs thicker synthetic because it does afford a little more protection in this extreme environment. For someone puttin' around town, it doesnt matter (that was your perspective about protection, I felt).
It really isnt unlike gear oils - a synthetic 85-140 will flow much better than a dino 75-90. So even though the synthetic is heavier (though it is approved by Ford in later 8.8's), it is a better product because it flows so well when cold.
Again, we are arguing minutia here. Danny uses what's best for his ride and I'm discussing a broader spectrum (I grew up in Alaska and now live in the desert - I got to see wide ranges of ambient temps and kind of have an interest in this stuff. I am a little non-PC [in this country] when it comes to oil selection).
