In term of Bokeh and rendering, this one is my favorite. This is truly a masterpiece of classic. I can't describe the feeling looking through Leica S OVF with it. It is in another world feeling, well, if you have good taste on how to appreciate what you see through finder
Because Contax glasses are designed to cover bigger sensor, they are especially suitable for stitch though I do find Leica S lenses offer the most native mount coverage compare to any other line of glasses I have used.