I've seen the Youtube video of the folding of a Dahon bike, but just trying to work out whether you really need to unscrew the pedals, undo the handlebar and remove the seat post in order for the bike to fold? Can this be optimised to take less than 30secs when getting on/off the train for example?
I've rather not have to fiddle with a spanner on the train but I'd rather have a 26" bike than a 20"....
I've not folded the Cadenza (though I sorely want one), however the Jack I tested at a local dealer has (basically) a similar folding mechanism / geometry and it can fold up plenty compact just by folding.
You might inquire of the guys at thorusa.com, they're usually pretty up front about the Dahons. They hang out here a good bit too.