Well, we did it. We cycled 400+ km along the coast of Poland from the German/Polish Border to Danzig in Poland. The road conditions were “adventurous” here and there but never a big problem. It was always fun. Most of the campsites were nice, clean and cheap. The train trip back to Germany (from Danzig) was no promlem, too. But there are almost no trains to the inland, just busses and they don’t take your bike on the bus (from what we’ve heard).