I have the Large Kelly Kettle I love it.
It holds the same amount as my kettle in thou house and boils just as quick, (I tested it in the Back garden)
I have the cook set for it as well which is a great add on and since it fits in the base it takes up no extra room
But!!!!!
Its Heavy & Bulky
The is no secure way to carry water in it
So as long as your vehicle based instead of hiking its perfect.
I keep 4x Sea to Summit X Mugs, A Spork, A Strikeforce Ferro Rod & some sachets of 3 in 1 coffee in there as well.