Hi I'm back. I was told everything was within spec and all they did was load new firmware in the 300 2.8 II. Could be psychological, but no matter, I will now brag I have one of the sharpest 300's around and do my best to capture shots that do it credit. I haven't had much time to play but got some low light ISO 12800 shots and some evening shots at ISO 1200. Here's a couple samples with the 6D 300 X2 III.Lovely pics! The one with the reflection is exquisite!