There are a few considerations regarding IBIS that occurred to me as I've experienced it which can affect shooting styles one way or another. Please forgive the lengthy explanation in advance
I've now worked with three successive Sony cameras featuring IBIS: The A900, A99 and more recently the A7R-II owned by a close photo pal. Prior to that I worked with both Canon and Nikon using select OIS lenses.
I was a vocal proponent of IBIS because it stabilized all of my ZA lenses compared to just a few OIS solutions from CaNikon.
However, in my experience, none of these stabilization solutions are instantaneous, which may or may not impact one's shooting approach depending on creative objectives.
I really like the way Sony implemented IBIS in the A900 because it showed a small graph in the bottom right finder regarding the degree of stabilization being achieved. That viewing cue disappeared in the A99 and A7R-II and you had to rely on optical judgement in the viewfinder as to level of stabilization being implemented, which I find a bit more difficult.
My acid test for speed of IBIS implementation was the ZA135/1.8, Sony 70-200/2.8G, and especially my Sony AF 500/8 Mirror: (at 500mm the image in the viewfinder jumps around like shooting in an earthquake, so it is the easiest to see how fast the IBIS steadies the image shake). 200mm on the zoom also makes it pretty apparent. In either focal length, IBIS eliminates the vibrating aspect, but not the framing which still can swim about a bit depending on how steady a hand you have, or how quickly you shoot once the image stabilizes.
While IBIS implementation is reasonably quick, it introduced a delay that began affecting my personal "Decisive Moment" style. Of course, I could simply turn it off when not needed, but that is a PITA and just one more thing to remember to do while in the heat of shooting.
Here's a question for those who shoot with the A7R-II can a custom button be set to toggle IBIS on/off?
Now I totally understand some folks wanting IBIS for their work. It is a God sent for hand-held or lesser supported longer lenses, Macro, or really slow shutter speeds in low light with stable subjects. All those are distant second considerations for me since I do not use long lenses very often and when I do it's on a tripod or RRS Monopod. Same for Macro which is almost always on a tripod. Since I mostly shoot people, slower shutter speed situations with IBIS or OIS doesn't stop subject movement so I either jack up the ISO to get the shutter speed higher, or more likely use a slower shutter speed to "drag the shutter" while using the short duration of strobe lighting to stop the subject movement.
In retrospect, I'm less of a candidate for IBIS than I thought I was or put differently, it is valuable for maybe 10% of the images I shoot, while affecting the speed of capture of the remaining 90% to some agree or another.
I'm sure I'm missing something simple here, and have no doubt will be corrected