No experience with the old 45 Superrotator, but I'm on my second 40mm Superrotator Hartblei Zeiss. It's based on an improved formula (coatings optimised for digital and movements) of the legendary Zeiss Hasselblad 40mm IF.
I understand from third party sources that there is no real comparison between the two lenses - the old one was based on different, not Zeiss optics.
As far as the new 40mm all I can say it's exquisite. Amazing microcontrast and resolution (stopped down to f8), colours and drawing style that are both gentle, detailed and precise, definitely Otus level (I own the 28 and 55) + movements, - some APO.
I was forced to sell my 1st copy, always regretted it, paid new money for the 2nd one.