In France, we use to say "Face de bouc" for Fbook. It means "Goat's face". That's a perfect definition ! On Fbook there are noboby older than thirteen years old so I'm not sure that anyone on Fbook knows what a Rolleiflex is. There are many Forums as Apug and the Rollei List dedicated to MF photography. No need for an other.
I am on Facebook more often than any other site, because that is where my friends and family can most often be found, as we live very far apart. That said, I use APUG, Flickr and other sites for Photography related content. fwiw I am closer now to 50 than 40, and so are many of my Facebook friends.