I have been thinking about what will someday be considered the classy looking bicycles of our time and, after viewing countless pictures online, I have to say the Dahon folders can really pull off classy sport just as well as Brompton's pull of classy sophisticated. I mean Dahon's can be really beautiful:
And both the Brompton and Dahon can even complement each other well.
I can see having both... the Dahon being more of the sporty workhorse and "sacrificial" tough duty bike (trailer pulling, bicycle camping, anywhere you might bring your bike overnight and/or don't want to risk your precious Brompton), while preserving the Brompton for both more formal and casual lite duty (a double bicycle date, the daily ride to the office, the coffee house, where ever you have to look your best).
And with the all black on the Dahon pictured above and a Brooks saddle slapped on the Brompton, you really get that hint of antique and classic bicycle flashback from them. Very dignified bicycles.