I don't doubt the inefficiency built into IGH design, which is meaningless in commuting for me.
The advantage of being able to shift while braking or at a dead stop is the major reason that I use an IGH on my town bike.
Being in the proper gear to launch with unruffled dignity from every traffic control on the route outweighs the drivetrain loss and mass of an IGH.

If I was that concerned about drivetrain efficiency I'd ride my fixed gear instead.....

-Bandera