What do you think?
Try the optyczne.pl comparison with the 100D.
It seems that lightning and exposure are much more similar vs the other samples:
After comparing the ISO-1600 samples, the 70D doesn't seem to be any cleaner than the 100D.
At ISO-12800, though, the 70D is slightly cleaner.
And comparing the 6D samples
(scroll down the page), I still see the same difference of 1.5-2 ISO stops
as between the 6D and the 18mp models.
So, overall, the 70D doesn't seem to be an improvement over the 18mp sensors in terms of ISO.
ISOs 6400+ seem to be slightly cleaner - but that's about it.
Oh, well. We can only hope that the 7DII will bring some real improvements.