I think you need a much higher level of tank maintenance if you're going to drink from them. I "shock" my fresh water system with chlorine every Spring (as per Peggie Hall's method) but then I still have water that sits months at a time in a dark tank. We use it for washing (and I use it to rinse my toothbrush, and haven't gotten sick). But I'm in your wife's camp, and use spring water when it comes to drinking and coffee/cooking. If we were going cruising long-term I'd drink tank water but only if I installed a final filter capable of microbial filtering.

You think your wife and I are nuts? It could be worse: Years ago in Coecles Harbor Shelter Island NY I saw a woman buy out the marina's entire supply of spring water, and pour it jug-by-jug into the tank of her Hinckley. Three dock carts full. Sheesh!