While there might be some issues with whether the actual growth numbers were real, the Soviet economy was doing marketly better than the capitalist west during the Great Depression, something that had wide repercussions on views about the role of the state and on economic control.
On the other hand, the German economy was studied extensively. And much of it was on public display--i.e. air shows, auto races, etc. Therefore, when folks discussed strategies for coping with the Depression, it was usually the German example that was used.
Thanks for your comment. "Remember the I35W bridge--who needs terrorists when there are Republicans"