In reply to Ramblin dave:
The heat exchanger pans all attempt to improve the fuel efficiency, at the expense of additional pan weight.
But consider that the canister holding the gas weighs about as much as the gas itself, so fuel savings are marginal, and only significant on long trips.
The other way to save fuel is to turn the burner down from '11'; use a low to moderate burn rate and you'll save wasting heat up the side of the pan.
The JetBoil et al are nice to have as hanging stoves, but they are heavier than more simple stove and pan, and usually have tall, narrow pots that aren't great for actually cooking on. Great for a fast boil, but not so great for cooking. The HX can exacerbate this too, due to the higher thermal flux into the pan. If your pan contents is gloopy (e.g. soup), you'll need to keep stirring. And you'll need a long spoon to do that.
If you're after speed of boil, good fuel efficiency, and a hanging or between-the-knees stove, then these things are worth looking at. Otherwise, a conventional stove may be better; you can buy HX pans for 'normal burners'.