Well....Ibis is great to have in video when you shoot video handheld. Is also a good ad of stabilization in handheld photo shots, but dont think is somekind of magic or you will forget your tripod.
From my perspective, i use IBIS in Sony a7R3 and the biggest advantage is to buy non stabilized lenses like the new ones from tamron (17-28 F2.8; 28-75 F2.8). So to me this is the big advantage, smaller and cheaper non stabilized lenses.
As a user perspective i dont see too many advantages, but is a good thing to have. And this is my point of view because for steady shots on video I use a gimbal or a Tripod. IBIS dont substitute neither!
Sony always hyped so much IBIS stabilization because of Vloggers. For me this are the ones that benefict the most of the IBIS. However....like i said before....its a great thing to have when you´re on a run shooting video and dont have a tripod, or if your lens is not stabilized.
For photography it can help you making shots with slower shutterspeed, like you can grab a 1/5 shot without a tripod with a 15/16/17/24mm lens. More than that I find hard to see a good pic.
In conclusion, it will be great to have on Canon Bodies, and i am curious to see how good it is and what the behaviour with the IS on lenses!
With or without IBIS just put the god Damn pro bodies outside!
Finishing line: Canon was right on this one: IS makes the same thing, or maybe better in stabilization!