My 50mm Sonnar ZM is my favorite 50mm lens. I enjoy it a little more than my 50mm Summicron, which is an excellent lens. My Sonnar is optimized for f/2.8. So from 2.8 through 16 the rangefinder on my M8.2 focuses the lens correctly. Wider than 2.8, the lens focuses in front of where the rangefinder indicates. So when I use it at f/1.5 I first focus as normal, then I move the focus ring toward greater distance until the split images of the range finder are about as far apart as the width of the white frame lines. That technique works on my lens for objects from closest focus out to about 30 feet (which is as far away as my lens will focus wide open). However, for close objects the DOF at f/1.5 is only a couple inches or less, so I need to have a very good reason to use that aperture for close objects.
This lens is very compact. The focus feel is excellent. The build is excellent. I like the color contrast it gives. However to my way of thinking, it is not magical. I am not sure that I could consistently distinguish images made with it from images made with other good 50mm lenses.