1) I'm not seeing the "impressive" cargo-carrying capacity at all. I don't see any room here at all to, for instance, add a cargo basket for carrying groceries. Maybe if there were more room behind the seat, but this would make the wheelbase ridiculously long, and it's already probably too long for use in a city environment.

2) I wonder how reliable the transmission is, and how much it costs. It seems like he's basically outsourcing a lot of the complexity into that one part. From what I've seen of geared hubs before, they tend to be very expensive compared to traditional derailleur transmissions.