I just went round and round on this subject my self. These were kind of my thoughts
Big bottle:
Pros: last longer, cheaper, less waste, refillable
Cons: Storage, whole bunch of flammability, finding refilling stations.
Little bottles:
Pros: Availability, Portability, storable
Cons: Wasteful, Expensive.
I was going to mount it on the rear bumper swingout but ran into some issues; namely the DOT code of it being like 54" off the ground, plus a lot of places dont allow HAZMATS and having a big ol propane bottle strapped to your bumper is just an advertisement. I ended up to where I am going to just keep running the little guys for now.