I would not use a Dahon for heavily loaded touring. I think they're useful bikes, but they are not designed for cargo hauling. So if you're the sort of rider who is going to want 40lbs/18kg of gear and food (or more!)... you'd be better off with a different bike. If you're more like Nun or Bekologist in terms of load, a Dahon might work quite well.

It looks like Bike Friday's Tikit can handle more aggressive load and more aggressive riding. Some of the stock models are around $1000, which is the same as a current Dahon Speed TR. Their more serious touring bikes run higher, and get excellent reviews even when the owner rides them quite heavily loaded.