The 9 or 10 stops of dynamic range you have here is not my idea of the "extreme" of pushing the DR. Film photographers routinely use 12-13 stops of dynamic range. I'd consider 17 stops to be pretty extreme.
Here is a good test:
http://www.fredmiranda.com/5DIII-D800/index_controlled-tests.html
5D2: http://www.fredmiranda.com/5DIII-D800/t/canon-mk3-2b.jpg
D800: http://www.fredmiranda.com/5DIII-D800/t/nikon2b.jpg