Hey thanks for the impressive pictures. Looks good! I like the beefy dropouts and fat welds in particular, good stuff! The Hanger looks different then what i thought..?
As for my experience with hub gears, it is all good as well. Both with the Nexus Three Speed and the Sturmey Archer. I really like they're durability and invulnerability. They never feel mushy or such to me and the range is enough for my style of riding. The difference in efficiency between derallieur and hub is rather debatable. I've seen many figures, none of them claiming a very large advantage for derallieur. All figures started from the premise that derallieur is "so many procents" more efficient IF the cogs and chain are new and the whole drive train is well lubed and in good condition. None too realistic a notion in daily use, particularly with a folder that is dropped back of cars or busses...
But anyway, different strokes for different folks. I also digg derallieurs for some applications/bikes myself.