As regards the components on the Brompton, they have proved to be reliable and very durable.... and they are of course readily available (try getting spares for a Dahon ) Some parts might look "cheap" (I thought the brake levers looked nasty the first time I saw a Brompton) but everything just works! I read in another post about "all roads lead to Brompton" and I can understand that! I wasted money and time on Dahons ... but at least I learnt a lesson... I learnt to appreciate just how wonderful my Brompton really is!
The Brompton parts may well be durable and Brompton does seem to have a good stock. I've read many comments from happy Brompton owners, so they are doing something right. But I look at the gear shifters and the rear derailleur and I just can't bring my self to buy one. I'm being a snob, but I know the first thing I'd do would be to switch out the plastic shifters for a better quality SA version. The Brompton is well designed for commuting, but would not be good for the longer rides and ease of repair that I want.
The issues with the Dahon sound annoying, but I'm looking at the Tern which has redesigned hinges and posts. I'll post my impressions of the Verge X10 when I get it.