Object Styles control over system families
Object styles do a good job at controlling the default display of most elements across an entire model in Revit. However, a finer level of control is often needed for basic family types such as walls and floors through the use of subcategories. Subcategories for system elements can currently be created and assigned specific line properties in the Object Styles window, however there is no way to actually assign an element or family type to one of these sub-categories. I suggest this latent functionality be made operational by adding an identity parameter to walls and floors so that they can be assigned to a subcategory, in exactly the same way that geometry in the family editor is assigned to a subcategory.
This would be very useful to control the display of different types of walls, floors, and roofs. Often for example, we will create our floor finishes as a thin floor which is separate to and sits on top of a structural floor - a common setup is a 10mm tiled 'floor' which sits on top of a 150mm concrete structural floor. Or a 20mm plywood floor sits on top of timber framing. The 10mm or 20mm floor elements should obviously not have the same cut line thickness as the big thick concrete floor, but there is currently no way of doing this without using view filters or manual overrides. Object styles SO VERY NEARLY gives you this control, but the loop is not quite closed to make it work.
The screenshot below shows how you can easily and intuitively make subcategories of system family categories, but there is no way to actually use them:
Autodesk - please make these custom subcategories applicable to model elements.