I don't know if your comparison is on the mark or not, but I will say that at ISO 3200 on the A77 II, I'm getting blotchy color shifts in the shadows that are visible at web size and can't be easily dealt with by naive NR (but can be dealt with through other means). That's the low light pain point for me. Same seems to apply to the EM5 and GH4.I respectfully disagree with you from a practical real world perspective The a77 has more dynamic range, better tonal range, higher resolution and more AF points across the frame than the 6d. The 6d will scale to higher ISO's with better noise handling and will hold onto color detail better past ISO6400. However I would wager that more people would benefit from better IQ at the lower isos' than the super extreme corner cases where you absolutely MUST shoot at ISO10000 without any light modifiers, flash, strobes etc... Most people want to keep their ISO's low to maximize their equipments IQ potential, and in the lower ISO's where you want to be shooting for most subjects, Sony sensor technology has Canon beat currently, even when comparing APS-C with small format.