The removable water cans are so convenient I didn't spend much time considering a regular RV water tank. I'm sure there's pros and cons for either method but I regularly camp where hand pumps are the water source. An external hookup wouldn't work. The other big one for me is not having to worry about sanitizing the tank or skunky water. I know from using the same small jerry can for years that as long as the tank is dried after each trip that's not a problem. Also this way the van plumbing is that much simpler.