Efficiency study table can be seen here.
www.DutchBikeBits.com: The stealth "near-fixie". An efficient bicycle for everyday use
This measure of efficiency is not gear ratio but actual energy transferred from crank to road. Single speed is most efficient, Rohloff and derailleur are the same (within variability across gears). Worst is Nuvinci and then Alfine 11 at low energy. The range of efficiency ranges from 78% (Nuvinci) to 97% (single speed).
A common advantage claimed for Rohloffs is reliability. Back in 2009 I search the net for reports of Rohloff failures. You can read about those here. I suspect the failure rate is higher than most believe, but probably not high enough to worry about. I would not use Rohloff on extensive tours in remote areas because the derailleur system, as previously noted, can be serviced at so many locations.
http://www.bikeforums.net/touring/51...ml#post8409218