Non-category specific behaviors...

So, the first question we should all ask is "what are categories really for?".

I think this is the fundamental root of the "problem" we have right now. Like many tools and features in Revit (worksets anyone?) the actual intent of the tool has been left to pasture and instead it is being using for many additional things it was never intended for.

My position on all this is that categories are simply a tool to assign non-geometric data sets (classes) to objects in an efficient manner. In other words, instead of you and I having to manually associate multiple parameters to objects one by one, we can make something a "wall" and certain parameters and properties are inherited as a result of that choice!

Basically, assigning the "wall" category associates anything that we deem as "wallness" to that element. Sounds good to me? You?

But, what it Autodesk or other users have decided certain things should be included in the "wallness" that you or I think otherwise? This is exactly what has happened with the wall tool. The only supported way to make a wall category object is with the wall tool. This tool not only assigns wall properties, it also creates the geometry using a layered construction assembly wizard. Right? You draw a wall, and as Shrek would say, "it has layers donkey."

But what if we're drawing a panelized wall system? It's assembly type is no longer "layers" but "panels". We can make a panelized construction using the curtain wall or curtain system tools, but we can't call them a "wall" anymore. Same thing goes for ceilings (ACT anyone?). Autodesk (and formerly Revit) have forced our hand and told us "all walls have layers" and "no walls are panelized except glazing". That leaves us with two options: Grossly misuse the tools we are given to correctly model the things we need (use a curtain system for ACT) or grossly misuse our time and attempt to model something panelized using a layered construction tool and adding reveals to it to mimic panels (like a metal panel wall or ACT). You notice I didn't offer "use a surface pattern as an option... Surface patterns don't export to Navisworks or any other 3D coordination tool on the market, which means your panelized system can't get coordinated against properly. I don't think that is an option...

So, that is the real problem with categories in my book. That the program is associating non-wallness things with walls and gives us no supported option to get the needed result (a panelized wall).

Now, some people will say that all that "wallness" that gets associated with the wall category isn't that important. If your models stay in house and never leave, then you're probably right. But you also probably don't care if it gets better. If, on the other hand, your models frequently leave the architectural world and make it over into construction management and fabrication worlds (like ours do); then you probably do care. I can't count the number of times I've had to explain over the phone to a subcontractor, estimator, or project engineer why we modeled ceilings or walls as curtain systems. There is no reason we shouldn't have that modeling (geometry) tool available to make walls, ceilings, roofs, or whatever!

My 2 cents...