System Information
Operating system:
Graphics card:

Blender Version
Broken: Any

Short description of error
Blender shows only unique meshes in the stats and ignore instance meshes. So if the user have a scene with thousands of cubes the stats of the scene only will tell that he have 6 faces and 12 tris. This maybe could be originally a design decision, but I consider like a bug because when you edit a scene you expect a total polycount and user will have a incorrect information about the scene. It is a behaviour prone to errors.

It is like ignore the instances in the number of objects in the same stats.