I just found and ordered two more canteen cup stoves to add to my collection. One is for the US military canteen cup, another for a British army canteen cup.
From what I gather about the Caldera stove from reading about it online (never actually saw or used one).
*It requries some assembly before use.
*It is a windscreen and stand, but not a stove.
*It leaves the forest floor unprotected.
*However, it is probably very efficient.
There are a couple of things I like about canteen cup style of stove.
*Minimal assembly (appeals to my occasional sense of lazy, er, simplicity).
*Pot stores inside stove, thus helping to prevent debris from *getting in the pot.
*Some versions protect the floor, though some don't.
My next version will be to use two titanium pots, one nested inside the other, similar to stove 6 mentioned earlier. This can be used with solid fuel (hexamine or even twigs) or with an alcohol burner. I will have to drill air holes and support wire holes in the outer pot but it should be very light, around 3-4 ounces. This is for a combination solid fuel stove, windscreen, and stand.
I was actually thinking about all this a month or so ago after not having tinkered with it a while, but now you've motivated me to work on it a little more.