Jason, the performance may be reasonably steady from full to near empty but I just can’t buy the claim that it is an all-temperature stove. I didn’t have a stopwatch or thermometer handy at the time but I recall that on a couple of chilly days it took about twice as long to boil a small pot of water than it did previously on warmer occasions. These were mornings when I had to scrape some pretty hard frost off the windshield, and the canister was half full or more. After ten minutes or so, I got my coffee but remember thinking that I wouldn’t want to have to depend on it too much farther down the temperature scale.
Neither the instructions that came with it nor the Coleman web site (Xpert or Xtreme models) make any claim that it is a cold weather stove. Perhaps Campmor can give you a source and data for the claim. Better yet, has anyone at Campmor actually used it in winter? If so, I’d be interested in knowing just how cold it can get and still be expected to work reasonably well. There may be something regarding the altitude claim, however. I recall hearing somewhere that as altitude increases, pressure in a fuel canister increases relative to the decrease in outside air pressure.