Doesn't that go against the conventional wisdom that putting a FF lens on an APS-C camera would yield gains in IQ since the crop factor means you'll be using the center of the image circle, ie. sweet spot? Are you saying that this is not enough to overcome the extreme challenge of high pixel density of 10+ MP APS-C cameras? I haven't seen any such comparisons, but it's plausible.
So we've not only hijacked the thread, but locked it away
I run into this a lot with video too -- it's theory vs practice.
Yes, it goes against the dogma.
But it's hard to argue with fuzzy/soft/noisy images that have causes isolated to the lens itself.
Running around with both a FF and crop sensor, I have to always be sure I have the "good lenses" for those bodies, when putting together a backup bag. Sometimes that means cutting corners and crossing fingers, when there are limitations on weight or bulk that can be carried.
Shooting sports, I've been caught in bad places and mowed over a few times in my days.