That's why I sold my 24-85VR for the 24-70. But tact sharp images hit rate was like 70%.
When I used my FM2 previously, the sharpness was superb. Even my wife also said so.
Thanks for your suggestion and guidance. Will try it out. Care to explain how does the sharpness problem being magnified? Is it due to more details, and showed out more if I do the pixel peeping?
Sorry to TS for the OT. But I want to know more before jumping in.
If sharpness is superb on FM2, which is manual focus, and only 70% on AF, then it is quite certainly due to AF fine tune or variation due to dynamic-area AF. AF fine tune, in simplistic language, allows for sample to sample and lens to lens variations to be catered for. If the camera is set for dynamic-area AF then it may not focus on the area where you are looking for the tact sharpness. I am now ruling out technique as you said it is superb on FM2, but did you account for the difficulty in pixel peeping the output of FM2?
OK, pixel peeping - I will say this is viewing at 100% on the computer screen, i.e. 1 image pixel is represented by 1 screen pixel.
For argument sake say your screen resolution is 1680x1050, and the imaging program you use is showing 100% over an area of say 1200x800.
So if we take a photo from a 12MP camera, say D3s (resolution 4,256 x 2,832) and you view it to 100% (over a computer screen area of 1200x800), you are seeing 1200/4256 ~28% of your image captured (the other axis 800/2832 ~28% also).
Now go to 24MP, say D610 (resolution 6,016 x 4,016), at 100% you are seeing 1200/6016 ~ 20% of image captured.
At 36MP, say D810 (resolution 7360 x 4912), at 100% you are seeing 1200/7360 ~ 16% of image captured.
You are magnifying a smaller and then smaller area of the image captured so it gets harder and harder to be "tact" sharp, given the same focusing / handling technique.
Or what looks sharp on 12MP could become less sharp on 24MP and then even less on 36MP, if say lens quality is not up to scratch (not your issue), or handling technique (not perfectly still when squeezing the shutter release), or focus on the nose instead of eyes.
Hope this helps. If it helps you do report back.