"I cannot tell which of your shots was taken with which lens and update."
You made my point. Thank you. 
"My 1D Mark IV is starting to show it's age. Newer camera bodies seem to get much better performance ..."
Man, I really, really don't agree with that. It makes me think you have something else going on besides out dated FW.
My 1d4 has been used with dozens of 'newer' lenses absolutely no issues. It works beautifully.
" I am not sure how they were able to fix an OS problem through firmware ..."
That (OS) and the focus point or focus speed is all they can basically do. Once the lens is made, assembled, it is as sharp as it is ever going to be. That can not be changed unless a physical part or component is changed or altered.
Adding compatibility with newer camera models is another reason for the FW updates and the dock. If doing these things makes the lens appear sharper all the better.
Bottom line you are now happy with it, so all is good. That's the important part.
@ebiggs1 wrote:"I cannot tell which of your shots was taken with which lens and update."
You made my point. Thank you.
"My 1D Mark IV is starting to show it's age. Newer camera bodies seem to get much better performance ..."
Man, I really, really don't agree with that. It makes me think you have something else going on besides out dated FW. My 1d4 has been used with dozens of 'newer' lenses absolutely no issues. It works beautifully.
" I am not sure how they were able to fix an OS problem through firmware ..."
That (OS) and the focus point or focus speed is all they can basically do. Once the lens is made, assembled, it is as sharp as it is ever going to be. That can not be changed unless a physical part or component is changed or altered.
Adding compatibility with newer camera models is another reason for the FW updates and the dock. If doing these things makes the lens appear sharper all the better.
Bottom line you are now happy with it, so all is good. That's the important part.
I can read. You identified which lens was used with which photo. I do not see a difference, or any improvement with the Sport. If that was your point, you’re welcome.
Yes, the 1D Mark IV is starting to show its’ age. It is great at shooting stills. But, the AF system in the 7D2 is better, as is the 45 point AF system found in the 80D. The 5D3 outperforms it, too. It can track very well, but it is just that the newer bodies are better at it.
True, once a lens is assembled, it is as sharp as it is going to be. That does not mean that using the lens in AF mode will yield sharp photos. Some lenses back/front focus, and may benefit from a micro-adjustment. If you can get sharper photos by manually focusing, then the AF system is flawed. If you can get better results with the OS turned off, then the OS is flawed.
Ii noticed that if I turned off the OS, the lens could focus consistently, which does not mean if focused well. The Canon AFMA uses two points to adjust focus. The Sigma Dock uses 16 points, which can add up to a lot of testing. I noticed the lens ranged from front focusing to back focusing, as focal length increased. It also ranged from front focusing to back focusing as you increased distance. The OS system was useless if you were panning with the lens, or even if you shot stills from a tripod.
Somehow, Sigma managed to correct all of the issues through firmware. The lens had always missed focus. The lens focuses faster, and quieter. The OS system now works like the way an OS system is expected to. You can pan with it now. You can argue a distinction without a difference all you want. But, the lens system is sharper now. It is as sharp in AF mode, as it is in MF mode.
