Thanks for the answer @inno , you are always very helpful!
You make the method work! 
Anyway, tt seems a bit strange the values you are getting, doesn’t it? For the cube sample you should get aspect ratios close to 1, since the geometries are closed to squares
Also for the sphere, it seems that the aspect ratio provided very distorted values although the elements does not seem so
The method I provided only works for planar 2D elements, which is the case I am looking for
Not sure about what this method is doing. Are we missing something else @dale ?