I have a UK Light Cannon (big, bulky and heavy, although not the biggest around), and I have both the lantern handle and the pistol grip, and have tried both. It's pretty hard to decide. Right now I'm using the lantern handle.
I have a fantasy of making my own Goodman-type handle for it, to fit into the dovetail slot like the others. I work in a machine shop, so it wouldn't be too hard to do, it's just that at the end of the day when it's time to decide do I want to stay another hour or two and work on this handle, or go home and relax, well, so far it's just a fantasy.
I realize just putting a Goodman handle on a big bulky battery case like the Light Cannon probably won't work very well, but I won't know for sure until I make one and try it. Who knows, it may work just fine.