I spent a little time tooling around on my mother-in-law's Dahon one day, but it was before I was considering getting a folder for myself, so I didn't pay close attention to what model it was. I remember that it felt spindly--I felt like I was a bit teetery on the seatpost. She may have a 16" wheel model, or, I simply wasn't used to the smaller size yet (my previous bike was a cruiser/mtn bike hycrid with 26" wheels).

The next time I'm visiting, I'll have to make a more purposeful comparison. Just from having shopped around, I feel like Dahon generally does a better job covering all the bases of accessories. I love the built-in dynamo headlight, for example, and I like that the Ciao has more speeds than the Barcelona, but in most cases, I can't use the frills to justify the price.

As for the other major brands that are regularly discussed in this forum, I have no experience at all! I'd never even heard of folding bikes until my MIL got hers, and then it was only last year that we got our own. I was frustrated while shopping that very few bike shops has models for me to try--that seems to be one of the big obstacles in really being able to shop around.