Think of any loss of efficiency as increasing your strength for racing by trying to commute at the same speed as on the derailleur bike.

I have 5 IGH bikes currently from a Sachs 3 speed Torpedo hub converted Kona cruiser to a Rohloff equipped bike and like them all. Currently assembling a Shimano Alfine hub equipped old Peugeot PX-10 road frame which will have drop bars and use the Jtek bar end shifter.