In this case, it was in combination with Di2. It let him build an incredibly clean bike. One cable and one thin wire right along it down the down tube and under the BB, no cables anywhere else on the frame itself. It was just gorgeous.
I was vaguely considering the same (again, gorgeous and clean), but I don't really think it makes sense for my first bike. I don't intend to go digital on my shifting, so three cables fixed to the frame are an unavoidable reality. Moving them all to the down tube won't yield the same "almost no wires" look, even if it shifts them to a slightly less visible position than the top tube. Plus, this is going to be a muddy super-commuter if I do it right.