Hmm... very interesting.  Thank you, phantom3D, for your generosity. I really appreciate it.
Sounds like a lot of experiment went through your rigging lab...and it's very inspiring to say the least.   
 I mostly work on body morphs to correct many of the bending issues, or to compensate joints.
When I saw the  v4 image of yours, I was shocked how natural it came across. Maybe someone can post the link to that v4 image, and I think it's worth seeing it  again.

Different grouping for the hip area means completely separate morph project. But I think it's worth the effort.

Thanks,