What I mean to say is that object size (the Size X, Y and Z on the transform properties panel) is a scaling factor rather than an actual size.
If I create a square plane, it defaults at 1x1 BUs. If I enter editmode, and move the vertices to make it a 2x1 BU plane, Size X, Y and Z in the transform properties panel will still all be 1.0.
I definitely agree that Blender should remain an artistic-oriented application, rather than CAD, but I don’t think what I’m looking for is related much to CAD. What I’d like to do is quite important for large art and animation projects, where many different props/sets/characters are stored in different scenes.
What I’d like to do is have a set of input boxes with BSizeX, Y and Z. Where BSize is the size in that dimension of the object’s Bounding Box. So when I move those vertices to make the 1x1 plane into a 2x1 plane, that change is visible somewhere, and I can scale based on that.