Well this is my own view, based on some input from John, what I read in online message boards as well as what I see in online videos and images.
I believe the Americans do not really know how to separate true working lines of the DDR from the show lines of the same DDR. DDR dog by default does not mean working dog / line. The DDR had their own show lines and I came to learn, in the last 4 years or so, that many seem to either ignore or (much more likely) don't know / realize that. Also, I believe MOST of the DDR dogs the Americans bought after the Wall came down, were of show lines, for two reasons - one would be, the east Germans, really, sold (mostly) good looking crap to the Americans especially since looks seem to be very important to the American way of thinking (not just when it comes to dogs). The other reasons would be, the really good working dogs were taken by others, such as the (former) Soviets.
Please remember I ams saying this based on the above mentioned, not real-life experiments.