I've got a Dawes folder its nice for a 20" wheel, also made the mistake earlier of buying two Peugeot small wheels (12" I think) positively dangerous steering geometry.
IMHO 20" or higher best for anything less than perfect road surface.(towpath and you might end up in canal)
I like the looks of the Mezzo (£400 more than mine) close to the looks of a BROMPTON (all bow) and as fast to assemble, and no bits sticking out to rip your skin as you go over the top.
A nice bag for it is a must.
John
I'm envious of your "Mezzo" bikes
It amazes me how the folding bicycle is evolving, with more models coming onto the market with the electric cycle closely following on.
I believe I saw a "Gocycle" while passing over the canal close by, which must be an extremely expensive commuter machine (http://www.gizmag.com/tag/bicycle/).
Like computers their constantly being overtaken by the latest one, the market is there for a instantly available machine and it seems to be lucrative for the moment.
John