I think SOME of what is going on with the odd ADS feeling is that there seems to be an animation bug/delay when attempting to ADS when you are in a sprinting state.
I've noticed that when I'm sprinting and I try to ADS at a target i always end up over flicking. To compensate this I've changed the Sprint Behavior to Hold instead of Toggle. When I want to ADS I let go of my sprint button at the same time I click MB2 and I am able to track and flick accurately.
This theory might explain why @DPI Wizard isn't able to replicate the sensitivity issues we are having, as he is likely performing these measurements when standing still, as opposed to run and gunning.
I could be wrong, but changing Sprint Behavior to hold instead of toggle seems to have resolved my issues (In addition to changing my monitor distance to 0%) This attached ss is a game or two after I changed the settings if it's worth anything.