Bill-


Those are great.


I'm not sure a 400mm prime would have helped your sharpness that much, at least not the f/5.6. (I'm not basing that on experience, but rather by comparisons of 1-1 crops of the 100-400 with the 400 f/5.6 on this website, so take it for what its worth).


More focal length would help. []


Jon.