We have a Dahon Mariner and a Downtube 9FS. The Dahon is much better built but more expensive. The Downtube has front suspension and it's way more comfortable to ride.
The seat sucks on both of them, I replaced them at the first bike shop we found. One fits in the baggage and the other on the back seat.
Downtube sells a bag for their bike, it makes it much easier to put it in the plane without worrying about scratching the paint in the baggage area.