It would be inherently more efficient, able to use a smaller and lighter motor because able to take advantage of torque multiplication of the transmission. A normal advantage of hub motor is that it doesn't put wear on the chain, cogs, and chainrings. However with a Pinion, if the gearing is durable, especially in constant oil bath and no grit like external gearing, plus a belt drive, I think the mid drive gearing could be just as durable. It sounds like a superb package. Hopefully it has a good clutch system so can be pedaled manually with no motor drag; With an easily-removed battery and smaller motor weight, that makes riding in light non-electric mode much more feasible, and also may be a critical factor for applications to folders, if the gearbox and motor do not add too much weight versus conventional gearing.