Bertins aren't that common, but there are more than a handful here on BF. As for appreciation: hell yes. Not sure what my bike is made of, but it's light enough, and tough as nails. Atom 3 spd; I've toured on it. It's the one bike I know nothing will be wrong with.

Mine is an early Belgian made Bertin. More pics on my webpage @ http://www.bygonebicyclist.com/?p=714