Eventually, I purchased the new camera called Sony α7Ⅱ, after I compared and confirmed the specification of Sony α7RⅡ. As the result, I am very satisfied with this choice, because, so far, I do not have the 4k system and the lens variety. I am using only the Leica Summicron 50mm with the mount adapter. Near the future, I would like to introduce how to use the Leica lens as well as the old lens. If you want to use the wide lens, which is less than 35 mm, I would suggest that Sony α7RⅡ should be the better option in terms of the picture quality at each corner without the less light. On the other hands, if you will use the basic lens like 50 mm and 35 mm, I think Sony α7Ⅱ will be satisfied. In summary, Sony α7Ⅱ is extremely nice body to use the variety of lens.
Finally, you can see the recent test pictures.
Amazon JP -> SONY ミラーレス一眼 α7 II ボディ ILCE-7M2