I've seen pictures of them and they are a beautiful rareity indeed. However nothing was mentioned of their characteristics. It is difficult to find such complete info on many common breeds much less the rare ones you seek.
Hopefully someone here can share first had experiences so you settle with the correct breed choice for your home the first attemp.
Just was looking on internet about bar-headed geese and saw your message. I got lovely youngsters if you are still interested, you also can see their parents. They are great birds to keep and very good parents.