Dave over at LearningDSLRvideo.com has posted his new comparison between the 5Diii and the Canon 6D:

I agree with most everything Dave describes.

– There was an issue with the 5Diii’s ability to focus with the AF lamp on the Speedlite, but this appears to have been fixed with the latest 5Diii update. I need to run my tests when I get back.

– For noise in higher ISOs, I believe the 6D has the edge, especially at 12800 or higher.

– The 6D runs into buffer issues faster when shooting with RAW for stills, meaning that 4.5 fps is only good for a couple seconds.

If you are doing casual/portrait stills only, you will be plenty happy with the 6D. If you are shooting video or sports photography, go with the 5Diii.

Dave also has his video course on the 6D our as of this weekend: Learning DSLRs Course on Shooting Video with the Canon 6D Dave’s videos have an emphasis on shooting video, while mine are more general use with an emphasis on photography and very short video introduction.