I received the Zeiss 28mm today. It is not as large as I imagined. It is “fatter” than the others, but not as tall as the Zeiss 135mm APO, for example. It comes with and elegant box, indeed, which for that money it should.
I have no photos to show you, yet. I can say it will not take any extension, which I would expect from a wide-angle lens. I can use the K-1 Ring on it, which is 5.8mm extension, but I doubt that I will often. One thing: it is very hard to focus, again a feature of many wide-angle lenses. I have not been able to get control of it… yet. It is heavy. The focus throw is not very long, which I don’t like. Will update as I have something to look at.