JR said:
There are too many of us experiencing softness in the image for it to be purely user error. Something is weird here.
Or several somethings.
1) Recall there were many complaints about the 7D's AF system, too, when that camera was released. So, there's a component of AF system complexity. Using an AF mode not well suited to the task (e.g. Spot AF for sports) can result in blurry shots.
2) Many people don't have a strong understanding of how an AF system works, in particular the fact that an actual AF point is larger than its representation in the viewfinder (even with Spot AF), and that the AF system will lock onto the feature that gives the greatest phase difference at the proper orientation regardless of where in that AF point's area the feature falls.
You know you're focusing on the eye, but if the hairline falls under the selected AF point, too, the camera may lock onto that as a stronger contrast - it neither knows nor cares that the eye is centered under the AF point.
3) There is a known issue with DPP that results in soft images with RAW conversion in High Quality mode (but not High Speed mode). At this point, ACR to DNG seems to be the nest approach, but it's an RC not final, and it doesn't run natively in LR yet.
So, it may be that if you combine all of these different factors, that accounts for the '5DIII image softness' - different people with different problems, all leading to the same result. Of course, there may be an actual hardware problem at play here, too - time will tell.
