I have a 35gal main freshwater tank and two 7gal Aquatainer water cubes. Filling the tank with the attached potable hose is easy, neat, and very fast. Filling 7gal the aquatainers at the spigot is splashy, slow, and they are really heavy on the way back from the spigot.

So before refilling the main tank I top off the 7gal aquatainers in the van from the main tank. This way there is no lifting/carrying and I only have to fill the main tank by hose at the fill station.