Ok, so I got my USB dock today and put it to work. I measured and taped the floor at the 4 distances (1ft, 1.3ft, 2ft, inf (15ft)). I had the camera on a tripod, and was shooting at a cereal box that was on a chair. All shots wide open, ISO was at 800 indoors and out, and I adjusted the shutter speed when I went outside. I setup the same way outdoors as well. I took photos at each distance at MA settings of 0, +5, +10, +15 and +20 on my 5D3 (mine never requires MA in the negatives). I then installed the firmware, and repeated the above shots indoors and out.
Indoors Pre-Firmware+10, +20, +13, +11
Outdoors Pre-Firmware +10, +5, +5, +10
Indoors Post-Firmware+10, +10, ~+10, +13 (some of these were acting a little inconsistent)
Outdoors Post-Firmware+10, +10, +10, +10
So basically, I set my 5D3 MA to +10 and took some real world shots inside the house and out. Overall the lens was behaving VERY well, and is without a doubt more consistent inside and outside lighting. The only real world shots that might have been a tad off were infinity outside shots, but I'm willing to accept that, and I don't want to mess with plugging in different MA settings via the USB dock at different focus distances since MOST distances are now behaving very well at +10 when set through the 5D3.
To summarize, the firmware update by itself made a nice difference with my lens. And as a side note, the evil part of me wants to return the dock now that I've got the firmware update : ) muwahahaha (j/k I'm not that type of consumer)