Upload & Sell: Off
I have about 100k images on my MIIn. The camera is a monster at tracking moving objects [sports], but does tend to hunt on stills...particularly smaller objects [flag poles, flower stems, etc]. Your f4 lens may also limit the number of active cross sensors.
I have found the best "overall" focus, for me, is C. Fn 13 set to #1, C.Fn set to #1 & C. Fn 20 set to #3.
Also, as great as the focusing is on the MIIn, it really doesn't come to life until you hook up a 300 or 400 2.8. The combo is unbelievable. You can tell, when using one of these set ups, why so many pros used [many still do] the camera. It is like night/day when compared to all the other Canon lenses I've used.
Lastly, for whatever the reason, I've found that whenever I tried to use the focus button, rather than the shutter for focus, I had terrible focus luck. Don't know if it was my technique or the camera. But, my keeper rate jumped dramatically when I used the shutter release for focus.
Best of luck. It took me [and many of those to went to the camera at the time] a good few months to really understand the focus system. But, once mastered, it really is a great camera. Even after getting my MIV, I still like shooting the MIIn.
Best of luck