So, you're asking the dumba** homeowner this question. My recollection, however, is that at the time we installed out Bosch unit, the "normal" plumber we were working with on our house remodel project subbed the installation of the dishwasher to another plumbing company. When I asked our general why his plumber did so, his response was something that caused me to think that there was some sort of expertise/experience that the general's plumber lacked. Sorry if my explanation was less than helpful!