I really enjoy touring breweries and talking to different brewers. I'm always amazed at how much differing opinion there is about brewing.
The last brewery I went to had a German brewhouse, with a sweet mash agitator in the boil kettle (I assume for decoction mashing? I don't know why else your BK would need a mash agitator.) They didn't do any decoctions though, so I thought it was an odd choice. Maybe they got a good deal on it or something.
They also just used regular municipal water run through a whole-house filter. I asked about their water hardness, since most of the water I've seen in MO is hard as nails. They said their water was really hard, and they tried to brew a Koelsch and it turned out horrible.
I asked if they had tried any softening techniques, like boiling or lime treatment, and the brewer said he doesn't believe in adding any chemicals to his beer. He didn't believe in adding any brewing salts either.
Their beer was OK, not amazing, but above average. They just make the kinds of beer they can with their water, and don't worry trying to make other kinds.