I use both
It depends on how much water I want and whether I need to use both hands while the water is flowing, so I use both pumps. I don't know how easy it is to access the electric pump in a new camper, but in my older Hawk, I could easily detach, drain and set aside for storing the camper in freezing conditions. The tubes to my pump are held on with simple hose clamps.
I have a friend with a newer Hawk and he told me how he set it up with a few valves, some tubing and extra clamps (he needs a crimp tool to put the clamps on, which are probably the same as came from the factory) he can use the electric pump to fill (and later flush) the vulnerable parts of the water system with the pink antifreeze (the stuff that's safe for potable water systems). I don't remember the specifics and I never saw it, but if I get a chance, I'll take some pictures and get a better description from him.