I did provide four links above. I know. you won't watch one of them (which is fairly clear about the disadvantages) because you don't like the guy but in this instance he speaks some truth.
The main issue is that it can mess with images at certain shutter speeds. This is true even of the superior lens stabilisation and I know this from experience. However with lenses you can easily turn it off without ill effect and this isn't the case with IBIS.
There are other issues which are outlined in the links also and I can' t be bothered transposing Ken's video to help you if you won't watch it so that's that.
For example, Ming says:
"Since the move to 36MP and higher, I’ve had enough images ruined by stabilisation mishaps under unexpected circumstances that I’ve now become very cautious, especially as resolution increases. As far as I’m concerned, the higher the resolution, the higher the tolerances everything in the imaging chain must be capable of achieving – and moving parts are rather antithetical to that. Stabilisation’s envelope of usefulness is no longer quite what we were used to – especially assuming that we want to maintain pixel acuity (and thus resolution) – otherwise we might as well just shoot smaller files. The sample images in this post were shot with a couple of different cameras under different circumstances, but illustrate clearly the difference between optimal and degraded acuity.
The worrying thing is that I’ve seen this behaviour from all brands – suggesting that we are approaching limitations of physics. Worse still, over time, I’ve seen on several lenses and cameras that internal components such as springs can weaken and begin to sag; this creates differences in optics when the camera is rotated (since systems are often optimised for horizontal panning) or even when stabilisation is switched off – often the lower or upper side of the frame is softer than the rest, as though something has slipped out of position. There seems to be no ‘good’ lens or camera or brand – over time (actual VR run time, not age of lens), all lens-based systems I’ve used seem to be susceptible to sag; the magnetically-suspended sensor systems are better, but can still return inexplicable results. I can’t help but wonder if electronic or leaf shutters plus better feeling release buttons are a better way of eliminating shake; for the moment, it’s stabiliser off – or better absent entirely – for me. Consider yourself informed if you’re trying to get the most out of your camera… MT"
Anyway, as I keep saying; you buy IBIS and be happy if you want to take the risk but to me it's just the latest new thing. I wish you happiness with it. I don't want it and would like to avoid it if possible.
There are some interesting issues being raised, both in Ming Thein's article quoted above
https://blog.mingthein.com/2016/08/19/stabilisation-is-good-but-only-up-to-a-point/ and also in this story from DPReview
https://www.dpreview.com/articles/5...m-f4-vr-to-fix-blur-at-certain-shutter-speeds but the situation is far from clear. I don't think anybody is saying that image stabilisation it in its various forms is not extremely effective at reducing camera shake at longer shutter speeds, but that it could in theory at least, be counter-productive at fast shutter speeds. This hypothesis has been around for many years, but there appear to be rather different concerns now being raised particularly with high resolution sensors, mirrorless cameras and shutter shock, plus the effects of electro-magnets in IBIS mechanisms and electronic first-curtain shutters etc etc. Some of these things, perhaps most of them, are related to specific products like the Nikon 300/4 VR PF lens that was recalled for a firmware upgrade.
The problem is, it's very difficult to test some of these things and to properly identify and isolate the issues. Ming T's article is frankly unconvincing - it's not good enough to simply say 'this image isn't as sharp as I think it should be, therefore the image stabilisation is to blame' when there could be any number of other reasons, ie more camera-shake than the system could cope with, subject movement blur, subject moving out of focus etc etc. The only way I can think of testing it is to take hundreds of pictures in a series of highly controlled hand-held tests, with and without image stabilisation, check the sharpness of every image and see if any trends emerge. Then do it all again at different shutter speeds, with different lenses, then across other brands. Many long days of work to do it properly, but even then I have a strong feeling that what would emerge would be the same as DPReview found (which is the same as my own brief tests showed).
DPReview said of the problematic Nikon 300/4 VR PF lens
"Furthermore, VR Off in either drive modes (Single Shot, or Mirror Up with electronic front curtain) can yield sharper results than any of the VR On shots, although 80% or so of your shots will be blurred from hand-holding shake. Still, the fact that the best you can get with VR On, in either drive mode, is worse than the best you can get with VR off is interesting." In other words, if you take ten shots at the most critical settings with VR image stabilisation off, you may be lucky (when the camera actually just happens to be momentarily stationary) and get a couple of very sharp images, but all the others would show varying amounts of unacceptable blur. With VR on, you'd get ten out of ten very acceptable images, even if none of them was
quite as sharp as the best with VR off. I know which I'd prefer though.
This theory about image stabilised lens elements and image sensors flapping around by themselves even when turned off doesn't sound like an insurmountablde problem, even if it's true (and I'm far from convinced). It just needs some kind of locking device, like applying the hand-brake rather than just putting the car into neutral at the traffic lights. Sorted.