In daily use,I really don't have any issues with riding and climbing with my BWR hubs. I'm sure that the guys in Le Tour would,but I really don't think normal people will notice the reduced efficiency from an IGH as much as they'll notice weight(esp in the wheels/tires) and gear range. When I was working at the old shop I would swap between my Pt Reyes and S6 for commuting and hub drag just didn't register.