In reply to tjin: Considdering you wouldnt peg your expensive, once in a lifetime trip on one pump and taking an entire spare would fall under good idea Plus considering that leather shrinks in the cold (sub30) the tiny leather cup in the primus can be a small problem similarly the old MSR leather cups.I would rather take three MSR pumps for the weight of one primus pumps.
A bit surprised that both stoves featured is ones that use a secondry conroller valve. Firstly they use far more spares and secondly, they are a beast to prime up in the cold and when the flame is dimmed at very cold temp they have a tenancy of stopping.That is why the XGK was invented in the first place. It has a much bigger vaporiser.
Admittedly it wont make a great fondue in the snowy mountains.
Jetboils on the other hand, an Alpinist's gift.