Sounds like it was a really great time. What language did most of the people speak there? I'm not even going to be so bold as to assume it was all English. I think that would be a huge barrier for me if I were to attend one of these gatherings outside the US.
I think the main language was English, we even had some lovely Americans in the group who were such great fun to hang out with. You wouldnt have any troubles with the language in german, usually everything is translated too.
That's pretty cool. Did the American's make the trip special to be there or were they expats that had moved to the area? It's cool that you got to spend some time with them either way.