I can't really say for sure if the Rollei version is different than the Hasselblad or not. And as far as that goes, my experience with the Zeiss optics is really limited to the Rollei platforms and though Zeiss made the same focal lengths for Hasselblad and Contax, I have never directly made my own comparisons if one were better than another. Maybe someone else knows? I do use the 120mm Zeiss on occasion. It is a sharp lens indeed (just not as super incredible as the 90mm Schneider makro). I have read people's posts that the earlier f/5.6 version of this lens might have been better but I've never tested it. For the Rollei there were several iterations of the 120 and in my experience the PQS version seems to be more resistant to flare which I interpret as better coatings. It appears that the 120mm zeiss is not neutral across the frequency range - meaning it seems to pronounce the fine details over larger shapes - and I think this yields a different look which might be appealing to some or not depending on personal preference. As to vignetting, I might be able to get that information for you later as I do have imatest files on it, but can't say off the top of my head.