i did about 900km this summer on my dahon matrix.
Man that's quite a lot! How did you solve the transportation problem of goods? Did you bought an extra carrier, used a backpack or something?
@ the threadstarter:
I have a Brompton and a Dahon Vitesse as well, both three speedster.
The Brompton is way rigid and almost say 'rugged'. This year I rode my Vitesse for abt 300km for short distances up to 15km even with 10kilograms of loadout. I deem it quite sufficient. Unfortunately since one month the vertical handlebar rod mounted on its hinge bracket starts squeaking and I cannot get calm by oiling which by the way is devastating to my inner calm...