The big news is the in-body five-axis image stabilization (IBIS). It’s the first time we’ve had this in a full-frame mirrorless camera. While the IBIS might not be as good as in the amazing Olympus OM-D E-M1, remember that this camera’s sensor has a mass more than 4x that of the E-M1. And for some, the real clincher will be that the A7II’s IBIS can be used with third-party lenses, even those such as Leica and other M-mount lenses attached to the Sony body via inexpensive adaptors. That’s right: the quality of that gorgeous Leica, Zeiss and other great glass now with image stabilization.
Other improvements are a much more robust body using more magnesium alloy parts. The results are a camera that is the same height and width, just a bit thicker and 100g heavier. Doug says it feels much better and more like a pro-level camera than the other α7-series cameras.