Of your list, the one that seems to fit the best to your requirement of being easy to carry and able to easily do 30-40 miles is the Birdy.
Its not as small and easy to carry than the Brompton but close tot it, and its much more efficient, much faster, much more comfortable and able to ride on any surface than the Brompton due to its stiffer frame, excellent transmission (not the City with Nexus one of course but the Touring with 10s or the Rohloff), full suspension and 50mm wide tires.
Electric assist on a folding is usually not as good as on a full size and increase a lot the weight with as consequence that the bike become difficult to carry.