Yes, PHD, I've seen those, but for some reason, my PP11 didn't come with it as the default Ground. Instead I got the old Ground plane I'm used to from earlier versions of Poser.
I did discover there's an Alternate Construct in the Scene > Poser 11 Environments folder. The difference between that and the Construct in the Props > Primitives folder is, the Primitives Construct gets "added" to the scene, but the Alternate Construct scene "replaces" the old Ground Plane, which is what SM probably did with the majority of PP11 setups, as I've only found one other person who received PP11 with the same old Ground Plane as the default scene.
If I didn't use BB's EnvSphere, and/or Snarly's EZDome, most of the time, I would probably have set up my default scene with the Construct, but up until now, I haven't found I really need it.