I’m currently pondering the merits of the two common designs of inspector window, i.e. these two:
Finder-style “segmented” inspectors use disclosure buttons to show or hide individual segments, whereas the iWork-style inspectors use a toolbar or a strip of buttons to control which page is visible. There are some applications (such as OmniGraffle, which used to use a fancier version of the Finder-style approach) that use a combination of the two techniques.
I’ve started a new page on Cocoadev if anyone would like to express their views on the matter.