The story is that I met a beekeeper in Germany with an impressive track record of 67 years experience with bees and every imaginable hive; he designed this hive and showed me the bees. I like it because it appears to be ticking most of the bees boxes, including nest site preference at a certain height.
I look forward to finding what will evolve with the colonies I housed in these hives this year. ---- Apart from all of that I find these hives very beautiful, and will suspend my next ones even higher, maybe 3 metres.
The originator of the hive has described the whole story in a book, now available in English (Sun Hive) Hope that answers your question. All the best, Heidi