My goal is to keep ISO at 100 as much as possible. If I do bump it up, I try not to go above ISO 400. Sometimes my composition must be adjusted quickly and I may not be able to get completely stationary enough to get a shake free shot. Like I said, my use may be different from yours. Were I to get an 80 megapixel camera for this kind of work, I would find IBIS to be very useful just like I do with my Olympus. IBIS and IS is not a solution for subject movement. So again, why do you buy IS lenses if you are rock steady? If you are trying to suggest that IBIS would not be useful, though you buy IS lenses, I think the point of what I think you are trying to say is just B.S. Why do you buy IS lenses? I can answer that for you, because nobody can always be rock steady at slow shutter speeds.. I shot several images this past weekend with a shutter speed of 1/60th of a second at ISO 100 @ f/1.2 and a 6 stop ND filter as the sun was going down and shining straight into the camera. Ibis would have helped a great deal. I've been published twice, so I am getting fairly decent at what I do. You wouldn't balk at at lens with IS, so what is the problem with in camera image stabilization?
By the way, last November I did two model boot camps where the outdoor temps were below freezing. Being from Texas I don't have cold weather clothing. There was a whole lotta shakin' going on.