I have ended up with an 'accidental collection' of Summars as I seemed to get one with almost every camera that I collected. In recent times I have started to buy them separately, including a rigid example. In the article I show some examples of the bokeh from this lens when used on a digital M. I also have photos of my Summar collection. The bokeh varies according to the f stop used and the subject matter, but it is always interesting. There are some examples in the article. I really like the output from Summar, a lens which has an unjustified bad reputation in some quarters.
The article is linked below.
http://macfilos.com/photo/2016/12/1/leitz-summar-review-the-last-rose-of-summar
William