Here in the north of England folders are not that common. I have never seen another Xootr Swift on the road and only the occasional Brompton. Local bike shops tend not to stock them even if they are supposed to be agents for a brand. I have only ever seen one Birdy in the flesh and that was over a year ago at the Tour of Britain near Alston - it wasn't in the race.
I bought my Swift via the internet with only a picture and forums like this to go on. In the UK cycling is seen as a sport or fitness activity, rather than a normal form of transport, so the dealers only stock what they know will sell.