The problem of the Birdy in Europe and US is that there are very few resellers.

In Europe, there are many Riese & Müller resellers, its the number 1 high end ebike brand but almost none of these Riese & Müller ebike reseller is willing to sell the Birdy and of course none has a Birdy in his shop.

I have a heavily upgraded superlight Brompton with a Rohloff transmission, a titanium Birdy and a Birdy 3 Touring.

Honestly, excepted for the folded size, the Birdy is much better than the Brompton: it rides much better (more efficient, more comfortable, faster, rides well both on paved and unpaved roads and trails, much better brakes), offer better luggage transport possibility (Brompton front block+big rear pannier+front low rider pannier) and has more adjustment possibilities to adapt to riders size.

For the folding and folded size, once used to fold the Birdy, its as easy to fold as the Brompton (many people say that the Birdy is less easy to fold than the Brompton but these people re mostly Brompton users trained to fold a Brompton). For the folded size, the Brompton is the smallest but the Birdy is not much bigger, its smaller than most Dahon and Tern.

About the Birdy R20 11SP (now called Birdy R by Pacific Cycles) I compared ETRTO406/20", ETRTO355/18" and ETRTO349/16" wheels on my Birdy and for me its a bad idea to mount ETRTO406/20" wheels on the Birdy because it doesn't allow to use tires wider than about 32mm (35mm without mudguards) and a big advantage of the Birdy is to have the possibility to use wide 50x355 tires. ETRTO349/16" would be as good as ETRTO355/18" if there were 50x349 but such size doesn't exist, the widest tire in ETRTO349 is 40mm wide and is a high pressure slick competition road tire.
Its a pity that Pacific Cycles discontinued the previous Birdy 11SP wit Hubsmith 18" wheels.