In Photoshop you can use the shortcut "f" to change the image mode. An option that I use very often. In CC there are some ugly bugs, which I can reproduce on 3 computers.
When I switch from the normal view to the first image mode, the image is always cropped and also not centered. Only when I move it with the hand tool the image normalize.
2) Again and again I have pixel errors between changing the picture modes. This also increases the source of errors when checking the image or you waste time because you cannot always say with 100% - display errors or actual errors in the file.