Bernard,
I too just received the Rodi 90hr. It is for use with an Alpa STC and IQ180. To give you some context of my comparison, the other lenses I own (or have owned) are: Rodi 40hr, 70hr, 100hrS; SK 43xl, SK 150. All the lenses I own for this system I consider excellent except for the 100hrS - it is fine stopped down but not great wide open. I have not tried an Otus, but do have (or have tried) a mixture of Zeiss (21,35, 100/2.0 mp), Leica (WATE, 90 'cron) and Canon (90ts, 70-200 f/4is) glass that I use on my a7R (also the quite-good Sony 55 FE).
So far the 90hr is like nothing I've seen to date. Wide open it has a Leica-esque micro contrast (draw?) along with a Zeiss bite that goes all the way out to as far as I can shift it with the STC, 18mm. When I saw the first images from this lens, I just shook my head. Wonderful lens.
I am waiting on the SK60xl; should be here by the end of July. As Paul says it is supposed to be close, if not equally good (and cheaper!).
Dave