" but everyone seems to believe the Neo's R-value is somewhat questionable anyway."
Thermarest gives the Neo Air an R2.5 rating .
Having used the ProLIte (R2.2) and ProLite Plus W (R4.6) the rating of the Neo seems accurate to me.
The problem is that people struggle with the idea that what is warm for one is cold for another.
IE when you walk around town with a jacket on , someone else will have a coat and next to him there will be a guy wearing a T shirt...
Having also used one uninsulated blow up mat, the Neo Air is definitely warmer than that.
Franco
Some trivia. In Siberia there are villages where schoolkids go out and play at intermission as soon as the temperature "rises" to -20c (-4f) or above.
I am pretty sure than in the US most headmasters would be arrested for doing the same.