About, the link, yeah i knew it is from and sponsored by Swift. Still most of what they have in that table seems balanced and sensical. They give kudos as well as question some of their rivals. I do find the table needs updating to include certain models by Dahon, definatley Downtube and others. As for the stifness of a Twenty frame, that is what i have heard and also what i am experiencing with my own. But the main things that make the Twenty frame crazy stiff is the very thick straight tubing (thicker than Brompton which is curved) and very much the fact that the hinge is unlike almost any other (definately. diff. to Brompton) because it is almost horizontal rather than vertical. If you look at pictures you will see what i mean.

But at the end of the day it all boils down to preference and what one finds more important. Perhaps we could somehow combine the best of both worlds in a hybrid design, that would be worth trying indeed.

In regards to Merc bike, hmm that is very interesting and news to me. Where did you learn that and do you have any links perhaps?