Thanks for the input. I already have a Brompton, but I was looking for a cheaper alternative for someone to whom €1.500 is a bit steep, although he does need the range provided by the six-speeder.
The Mezzo looks nice, but it has no front lug to hook up a Brompton carriage block; Besides, its unusual handlebar prevents putting a bag in the front anyway. Out of curiosity, I'd like to check the Mezzo you're selling. May I have the URL, in private if you prefer?
I saw a Curve D3 in a store this afternoon but couldn't measure its OLD: It's obviously less compact than a Brompton when folded, but it could be a good, cheaper alternative while providing a bigger gear range + easier shifting if fitted with an Alfine 8/11.