Thanks for your response, Roger. I always appreciate your learned insights. I happened to buy a JetBoil canister yesterday to try out. On the can, it says "Made in Korea." It happens that the JetBoil, MSR and Optimus canisters all are made in Korea, and they all have identical protective caps (maybe different colors). Hmmm...maybe all made by Kovea? Snow Peak doesn't mention where their's are made, maybe Japan? Their protective caps are different, and are stamped with "Snow Peak." My 10-year old CampingGaz and Primus Power Gas canisters were both "Made in France," so they're probably OK. All of my 4 ounce canisters appear nearly identical dimensionally, with the only apparent difference being the color of the metal as viewed from the bottom of the canisters--Optimus and JetBoil are a light gold color, the Snow Peak a bit darker gold, and the MSR is silver. Do you suppose that this is due to some sort of brass/steel composition differences?
I'm certain that I am over-thinking all of this, Roger. But that's what some geeks do to help pass the dark, cold days of winter. I'm just trying to study the canister weight/number of boils/ambient temperature performance of these various fuels. Maybe I should move on to dehydrating/vacuum sealing next summer's food supply instead?
Thanks again, Roger.