I have a Kelly Kettle in my collection of camp stoves. It is an interesting concept but not really a backpacking stove.

1. It's heavy.
2. It gets hot. That is, to pick it up and pour out some hot water is something you won't do with bare hands. There is no good way that I can see to grab it.
3. If you attempt to pour while the fire is still going you risk pouring embers or at least messing up your fire.

If your concern/desire is to have multiple fuel options, something along the lines of a Caldera Cone or the new Esbit stoves might better meet your needs. You can also do something homemade that is similar with a small pot stand and windscreen.