This stuff about hybrids limiting distance is getting kind of old. My wife and I regularly rode 50-60 km. (30 - 40 miles) last summer. She rides a Trek 7300 WSD and I ride a matching 7300. We didn't get tired, sore or discouraged at all. Actually we enjoyed these rides and plan to go further distances next riding season.
Furthermore there have been numerous posts about people doing self supported tours long distances on hybrids. So are we talking effeciency, time, or distance? I think those factors have a lot of bearing on the matter. Hybrids are never going to be as efficient as road bikes but that doesn't mean that centuries, for instance, can't be covered comfortably and in reasonable time. IMO it all depends on what one wants from the ride.