I believe that stove comparison could use an update, I am easily able to not only match, but exceed, what sgt rock reports for not only his cat stove, but (by far) the pepsi can stove he used, in my current testing, and that's with a simple penny stove that takes maybe 20 minutes give or take to make (how to will be forthcoming). And this is with narrow pots, not wide. A 900 ml and a 750ml, the 750 is slightly wider and squatter than the 900ml.
I'll post more complete results later, but this AM, for example, outside, with a real wind, not stove fan updraft, I was able to get a 17.5 ml boil of 500ml with over 1 minute of boiling, rolling, with a new pepsi can stove I tried this morning.
Last night, in tests, I got to 99.5C/211.1F temperature, not quite 100/212, but pretty darned close, using a digital deep fryer thermometer. Outside temp about 16C, water temp 25C, roughly.
I haven't yet tested minimum fuel to boil 500 ml in this latest pepsi can stove, penny style, modified, but it looks like 15ml would not be far off the mark, ie, 11.4 grams, ie, 0.4oz per 500 ml boil, which is only .1 oz per boil difference from gas cannister stoves from what I gather, give or take.
However, I am also finding that the height of the windscreen, when there is wind present, ie, real world situation, not indoor test, is very important, a 4" screen just does not cut it, a 5" one does ( assume there's a wind vortex or something that forms and goes down to the flame area at 4", but not at 5", not sure yet), with same stove/stand, slightly different pots, and wind screens 1 inch difference, it's interesting to see the differences, it's between a full boil with 1minute of boiling to not quite reaching a full boil at all, not sure why or what the actual difference is, I'm going to pursue that a bit more fully to see if I can pinpoint it, the shorter screen goes with a very thin walled stainless steal pot I found, so it may be a difference in how heat is reflected back to the stove, I"m not sure yet.
For economies sake, I am using slx, but for heaven's sake, do NOT use this stuff indoors, I consulted with a real chemistry professor, and he said students are not allowed to even open methanol without using the enclosed, ventilation fan running, toxic chemical handling boxes, whereas of course, ethanol is just fine. So the somewhat glib assumptions of safety re handling high methanol content fuels like HEET/slx might be worth a thought if you care about your health.
Re the cone holding up the pot, in early tests last year, or the year before, the heat would slightly deform the screen, and make getting the pot out a real challenge, which is when I stopped using method, I like to be able to lift the pot out easily, without having to get the screen off. That's when I decided to go with the straight screens, I'm suspecting that what is wrong is not the cone/no cone shape, but rather simply too short straight screens, which are too far from the pot walls, ie, diameter is too big. I'm using, after a lot of testing, pot diameter + .8 inches screen diameter, ie, a .4 inch gap. This can be easily tested however. But I have been noticing 4" screens being sold, and in my opinion those are too short, and will cost you far more in extra fuel consumed than they will save in weight.