That lens frustrates me to no end, but I keep going back to it.
I admire those who can use this lens. I've collected a lot of lenses over the years, but I've bypassed this one. I don't think I have the patience to setup and use it. I like the 100L, I can be sloppy and handhold it and get reasonable images. I do have a 5X Zoom long working distance inspection microscope with ring light that I could adapt to a DSLR. I mostly use it when cleaning my sensor.