Very good lens, w/ a spotty reputation for quality control. Mine imaged nicely, but it had been over greased w/ the usual gray grease, and put back together w/ the lens markings ending up on the bottom. It had arrived in the usual brown paper " box" that was wrapped w/ twine. Sending it back overseas would have been not fun.
I had bought it w/ a Nikon mount (which miraculously worked fine), and was using it along w/ a Leica R lens and an adapter on an N8008s, so it was only used in stop down AE mode. You got to see your DOF instantly when the view got darker or lighter,so F stop numbers on the top weren't really needed.
The over greased helical threads I just lived with. It was slower to focus due to the over damping, but tolerable. The R 90 Elmarit that I had was better but they were both very good, and of course the J-11s cost a lot less money.