You are correct PIRAT. The Berlin stock exchange is the famous corrupt exchange where companies would suddenly appear out of nowhere and be shorted to death. I have never heard anything bad or corrupt about the Frankfurt exchange.
The benefit I see going forward with this duel listing is it will shrink the float. For every share bought over there, the float will tighten one share. It will drive up buying pressure. Once listed, it will help drive the share price higher. It will be like how Microsoft and Intel have duel listings on the NYSE and NASQAQ.