It appears Canon has solved the banding issue? 6D!

You don't need to go to that extent, even more so as people complain of low DR and banding in regular shooting situations when lifting shadows.

You just need to lift the darker areas (that example is plenty fine for that).

Given what I'm seeing from Capture One, which is less sensitive to banding than Lightroom, I'd say that the 6D performs closer to the 1DX than the 5DIII, both in terms of banding and high ISO performance. So banding should be reduced, but I bet no eliminated.