Organize Project Browser by Discipline
Project Browser and the entire Revit interface should by organized by Discipline. Each professional (architect, engineer, drafter, scripter, etc) should focus easy on the tools they need, not searching the entire Project Browser database, scrolling endless categories they don't need, nor care about.
A structural engineer doesn't care about MEP categories or architectural entourage. A MEP engineer doesn't care about rebars and structural concrete elements.
Revit is created for many professions, why put them together in one giant interface they don't need. It is very tedious and time consuming to search that giant Project Browser with millions of categories in it. The interface should be customizable like the Autocad interface. The Revit interface and the Project Browser is familiar to not one particular professional, because it is amalgamated beyond recognition. It is like a Star Trek Borg clone. You just can't see what part is human and what part is machine, what menu goes to what profession, what category goes to what professional.