i was talking to my local camping store rep about jetboil and they mentioned a lot of people complaining about cold, winter use, and one of the blends turning partially to liquid, and "settles" to the bottom, so, it will never burn... could use it later in warm weather - maybe... same for MSR
the solution? there's a new model jetboil system with the fuel container UPSIDE DOWN, thus feeding liquid out, as long as there is [partial] pressure. it also features a fuel pre-heat just like the whisperlites. better, but yet available for their coffee/java system.
he also said what some people do is warm the fuel can inside their jacket, until they need it, boil a bit of water first, and pour that into a pan, and then immerse the fuel can into the warm water, and/or use a chemical heat pack UNDER the unit to keep it warm enough and keep the whole unit off the snow/ice - use a pad or board, or anything. a heat // wind ring around the base as well helps *a lot*... so, a bit more work, but off you go.
seems to me for winter camping, my old whisperlite is the least complex method, and the fuel is already liquid, so it's going to work in temps colder than i want to go out in.
for spring/summer/fall though, the jetboil is my coffee pathway
Bladite