Their main drawback is they aren't very cost effective, given they usually burn isobutane. You might save a bit of weight over a battery powered LED lantern if it uses the same fuel as your stove, but not much.
Frankly it's outmoded 90's tech. I don't see the practicality of it. I think I've heard some people use them in their tents in the winter, against the manufacturer warnings, because they can be a bit of a slow heat source or something, but otherwise just get an LED lantern or even make little things that convert headlamps to lanterns.
