If get it correctly, Joost would like that File->Open leads to the creation of a new window instead of a new buffer in the current window. I would like that File->Open behaves as it currently does, i.e., no new window. You can always open a new window and then load a file from there.
Maybe I am old fashioned, I actually like the way gvim and emacs works. Namely, there is no separate window, just panels. Correct me if I am wrong: The word way: every window corresponds to different document. A single window has panels (views for the same document). I do not quite like this since they will be too many windows. The old-word way (sub windows). I do not like it since there can be unused spaces. The problem with gvim is that close-buffer and close-window can be confusion. Maybe we should vote, but let us first see what Abdel says. Bo