I am only stirring when I say these things about Dahons, in fact I like the top end Dahons very much, so please don't be too touchy.....
I tend to spend my big $$$ on full size bikes, but SWBs do have a soft spot with me, I love the way they can ruffle the feathers of stuck-up roadies sometimes, I think we all suffer a bit from GraemeO'Breeitis, in our own way.
With modding a R20 they will never be as light as a Dahon, but yes, the frame is so strong.