Let me slip this one in for some variety... my friend's Batavus that was a 3 speed until yesterday that is now rocking a new SA 5 speed IGH out back to give it a little more range and climbing power and if that fails it has an electric motor in the front wheel.
My friend lives in the valley so has to be able to bring this bike up about 900 feet on very steep roads with a child trailer behind.
That new SA five speed is a really nice hub... shifting is wonderful and range is very good with a 24 tooth cog.