Full spec comparison between those four lenses can be seen on this BHphoto comparison page

Ted Forbes made a comparison between the new Sony 50mm f/1.4 GM and the Sony 50mm f/1.2 GM , Zeiss Otus 55mm f/1.4 and Leica Summilux 50mm f/1.4 . Check out the video to see the results:

Sony 50mm F/1.4 GM at BHphoto . Amazon . Adorama . FotoKoch . FotoErhardt . Calumet DE . WexUK .