I have theory on my side of the space blanket discussion. Check any intro physics or undergrad Thermal text. Radiative heat transfer is minimal at human-environment temps, especially compared with convection. Fortunately, I also have experiment on my side - as I'm sure you know, physical theory isn't considered "reasonable fact" until it's borne out by experiment.
I'm glad you make the distinction here between laboratory testing and personal experimentation. Until someone takes enough of an interest to devote some serious, controlled, objective lab time to testing a variety of insulations and conditions, there won't be what I consider hard evidence. Until then, we have to rely on the opinions and experiences of others. And when it REALLY comes down to it, we can't rely on anyone's experiences but our own.
I'll be sure to post my OPINIONS on the SS as soon as I get some testing time in.