Quirky? I never thought of those systems as quirky but I smiled when I read chast's post because..........they are a little quirky. But, they have worked well for us for over twenty years and we have found the systems to be reliable. I still pause when I try to remember which way those valves go to switch between the water tanks so I just always leave them combined and use both tanks. I suspect most owners do the same.
I have owned both a MG and a Austin Healey in my past and now THAT is quirky so I probably measure most things compared to "positive earth"!