Jim, when you say efficient, you are referring to some measure of liters of water boiled per ounces of alcohol consumed, right? Do you have figures on how efficient the Trangia is compared to some of the others.
It boils down to the ultimate question - how many days use will it take the more efficient Trangia to overcome its burdensome (3 oz!) weight? Enquiring minds want to know....
How is it possible that no one has as yet favored us with a Titanium Trangia (Tirangia?)?
Trangia did put out a Ti version for a while. I think just the windscreens were Ti. It was relatively expensive compared to the aluminum versions -- and the aluminum versions were (still are) already quite expensive. It must not have done well; it was discontinued. Part of what may have killed the Ti version was that Trangia changed their alloy. Their current alloy is quite a bit lighter than say my pre 1988 version. I'm not sure there was enough weight savings between the current alloy and the Ti versions to justify the cost.
There is a Titanium burner available from Evernew that is similar to a Trangia burner. It is not as efficient as the Trangia burner from the tests I've seen.
And, yes, when I say efficient, I mean the ability to do "X" amount of "work" (boiling water in this case) with a given amount of fuel. In my tests, the Trangia burner
in a stand alone configuration (i.e. without the patented windshields) was able to boil water consistently with less than 3/4 fl. ounce whereas many of the stoves shown in the photo above could not.
I haven't done the painstaking work to calculate the break even point where the greater efficiency of a Trangia burner makes up for the lighter weight of some of the aluminum beverage can burners. That's a lot of work if you do it right. Time hasn't permitted.
As a "short cut" (partially), I just "baseline" any alcohol stove I test against the Trangia burner. If it can't match up against a Trangia, then it's not particularly efficient. If it can beat a Trangia, then it's a pretty darned good burner. My Caldera Cone when used
as a system (cone + 12-10 stove) beats a Trangia in a Clikstand set up in terms of efficiency. I haven't compared a full Trangia 27 set up to the Caldera Cone (sort of like comparing an aircraft carrier to a PT boat, totally different class of thing).
HJ