We all know why a propellantless drive would be so important. The question is does it work. The answer seems to be no. This "load" argument seems like hand waving. I saw most of his recent web presentation and to my mind he did not give a very good explanation of this load argument. And according to him no load and it doesn't work, like in say space. It drives me crazy when people spend so much time on how important it is rather than theory or evidence.