Originally posted by luftfluss Again, it doesn't have to be a case of either/or. Pentax can do both, like Olympus, Panasonic, and Sony.
You're potentially paying for it twice, though, Luftfluss - glad money is no concern for you!
AFAIK, lenses can only do three way stabilization, IBIS in some other brands gives you the other two in conjunction with them. The best like Pentax and Olympus can do it all in the camera, so even a silky Takumar gets the benefit.
I do have a Sigma 150-500 with IS but I will turn it off when handholding because my K-1 has its five way IBIS. I will turn IBIS off and use the Sigma IS when I'm using my K-S2 or when doing a lot of panning on a monopod or tripod, because it has a special mode for that.