I tested the two SVEAs last night, boiling a quart of water and weighing to measure fuel usage. I’ll update later with the actual numbers, but the two stoves used 0.6-0.7 oz. weight of fuel to bring a quart of water to a full rolling boil, then simmer for a moment (I was also testing simmer capability).

I primed with about half a plastic eyedropper of stove fuel from the tank so that I’d include the weight of priming fuel in my total. It took two tries with the 123R, which also doesn’t simmer as easily. In short, the original 123 is lighter, lights easier, simmers better, and seems to be just as efficient. The only downsides I can see are the lack of a built-in cleaning needle and the crummy substitute control key. It’s a 123R key with the end bent to sort of fit.

It seems, by the way, that the old 123 doesn’t really need a rebuild at all. When I started to unscrew the burner what looks like a brand new wick came into view in the tank, so I just tunred it back in and left it as is. Too bad I spent the money on the rebuild kit and wick.