There has been a lot of stories over the last year or so from people that have left Canon for Sony, only to return later. A few of the big reasons we've seen for the return to Canon center around support, reliability, professional services and repair times.
The latest article seems to center around Canon's industry leading video auto focus and color science.
From PetaPixel:
Better Color Science
Overall, I feel Canon has much better color rendition when it comes to reproducing colors and providing natural hues in the way we expect them to look. I have spent a lot of time editing Sony video footage trying to get it to look right in post. When I shoot video with Canon Log though I simply apply a LUT (a Look Up Table file created and supplied by Canon) to my Canon video files in post and, with basically just one mouse click, I get more or less perfectly color graded Rec.709 footage. Something I can say isn’t as easily achievable with Sony. Read the full article…..
As I sit here in Tanzania, I have been surprised by the number of Sony A7 series cameras I have seen on safari. However, the numbers still pale in comparison to the amount of Canon and Nikon gear I'm seeing for this type of photography.