Notes icon
 

I think the Notes icon in lists could be a little darker when a note has been attached to an action. When a note is hidden it is a little hard to see that there is a note attached to the action. The note icon doesn't have to be too much darker, just a little bit to clearly differentiate it from an empty note icon.

I agree. I also wonder if thought has ever been given to moving it to left of the action (as it appears in OmniOutliner)...