I would like everyone to make a simple consideration.....
Looking at the last 4 Canon sensor generation
-1Ds mk II, 5D,
-1Ds mk III,1D mk III,5D mk II, 40D
-1D mk IV, 7D
-1DX, 5D mk III
Lets look at the pixel pitch and at the equivalent DR values for each generation:
5D Pixel size 8.2 = 9.2 DR
1DS mk III Pixel size 6.4 = 11.3
5D mk II Pixel size 6.4 = 11.1
40D Pixel size 5.7 = 11
7D Pixel size 4.3 = 9.8
1D mk IV Pixel size 5.7 = 12
1DX Pixel size 6.9 = ?
5D mk III Pixel size 6.25 = ?
As you can see each generation gave an increase in DR except with the 7D wich has an extremely smaal 4.3 pixel pitch size
Last generation sensor gave a 12 EV with 5.7 pixel size
The mk III has 6.25 pixel size
Even if Canon didn't progress in DR with the newest sensor engineering...
..... I have really hard time to believe that with the 5d mk III with 6.25 they can't get same or better DR results with a sensor that has 5.7 !!!!
Time will tell....
I think it's worth mentioning that using raw data to discuss low iso banding and dynamic range is VERY VERY misleading.
The usual testing methodology simply determines the lower end of the dynamic range as the point at which the noise overwhelms the rest of the data, ie a signal to noise ratio.
The issue with low iso banding is not so much that Canon's cameras have excessive noise at low iso, they do not have especially excessive noise, and the data proves this at only slightly more than a 1 stop difference between Canon and say Nikon. The issue however is that this low iso banding noise CANNOT be removed because noise reduction algorithms treat pattern noise as detail and do not remove it.
Noise reduction algorithms are currently good for about 2-5 stops of noise reduction depending on how tolerant you are of losing detail.
So while on paper the 5D II/III have aproximately a fantastic 11+ stops dynamic range. In the real world they have an earth shattering 3-6 stops less DR than tested because NR is ineffective on low iso banding.
So here is a question
Does anyone actually know what the useable dynamic range of any of these cameras is?
I'm not talking about the infinite naval gazing number crunching analytical sort i'm taking about where the line gets drawn between "yeah that looks good" and "OMG that pattern noise just tore my left eyeball out"
Its prettysubjective isnt it? so the line is going to be different for everyone
and then there is all the third party Noise reduction gear out there which can salvage something that was fairly poor and make it acceptable extending that range of use. I dont think comparing things like this soley based on some numbers is very wise.
Hope that also answers your question.