Several people in the Chicagoland Folding Bike Society have Dahons, both
lower end commuter bikes and higher end bikes suitable for touring, and
have had good luck with them.

The problem with Dahon and all other "off the shelf" folder
manufacturers is their failure to produce a man-sized bike. They all
have weight limits of around 230 lbs. which of course is too light for a
man (or larger woman) who might be traveling with perhaps a 50 lb. pack.
In the winter a rider might have 10 lbs. worth of clothes and boots on
as well. Take the weight guidlines seriously, especially for aluminum
bikes! You might be able to fudge a few pounds over the limit, but not
25-50 lbs.

Bike Friday will custom manufacture folders with stronger tubes to
support heavier weights (even as high as 350 lbs. AFAIK) but I don't
know how much more they cost than their other bikes which typically
support about 200-230 lbs.

-Bob Matter
Chicagoland Folding Bike Society
Dedicated to the promotion of folding bicycles
and enhancement of the folding bike experience.
http://www.geocities.com/rjmatter/