The Character and Paragraph panel blank out fields that have multiple values (when selecting text with differing formatting).
But, in the Layers Panel, fields with multiple values are displayed with the value of the whatever layer in the selection is on top. This is not only inconsistent, but can make the user incorrectly believe that the selected layers share the same value. It should be updated to reflect the behavior of the Character/Paragraph panels (and other applications).
Not sure if I should post this under "Idea" or "Problem", but I consider it a minor UI consistency problem. 🙂