I REALLY wish you'd have tested a 2"x3" glass signal mirror too.
That would resolve the question of whether the 2"x3" Rescue Flash's performance was a matter of size or material.
Understood. I've shipped my friend a 2"x3" glass mirror (and a 4"x5" stainless steel mirror, as well), and I'm trying to get more volunteers so we can do some side by side simultaneous comparison rather than sequential.