Dpreview added the A7rIII to their Studio Comparison Tool. SAR readers are welcome to discuss their findings. Seems like the A7rIII has more chromatic aberration and bit more sharpness than the previous A7rII. Noise handling seems to be improved too (Note the Canon in this comparison only goes up to 12800 ISO):
Sony A7rIII at Amazon, Bhphoto, Adorama, BuyDig, FocusCamera, Calumet DE, Wex UK. Photo Porst Neuwied. Sony Netherland. Sony Australia. Sony Japan.
Sony 24-105mm at Amazon, Bhphoto, Adorama, BuyDig, FocusCamera, Amazon DE, Calumet DE, Wex UK.
Join the A7rIII facebook group to discuss the camera features and tests!