They show up everywhere. I lived three years in a small Ohio city (pop. 50k) before finding out there was a FLW building in town. I had a realtor show me a few in Grand Rapids MI (though I really wanted to see housing I could *afford*).
The leaking doesn't surprise me. A visitor to Falling Water complained that water was dripping onto his seat, to which FLW is said to have told the visitor to move his chair.
They do. I grew up in a small Michigan city where, I learned much later, there are many FLW buildings. I pushed an ice-cream cart past some of the FLW houses, and our church building was designed by FLW.
Yeah...I'm a fan of his work. Many are in dire need of repair.