It would really depend on how much you think you'd want to upgrade on the Nano. (If you can get one...) By the time you're done futzing around with it, you could easily have as much into it as you'd spend on the Dahon. Thing is, if you got the Dahon, there might be parts you'd want to upgrade on it, too. Coming off an S1, I think you could get away with leaving a Nano stock and enjoying it, so if budget is a consideration, in your situation, I'd opt for the Nano, live with it for a season, and then consider upgrades.