I had the 90, 180, and 150 purchased in that order. The 150 gave the beautiful soft effects I was after. The lens is hard to use as you need to focus at shooting aperture and that can be a dim image under strobes. It is also a bit short for head and shoulders on 6x7. Stopped down it gives sharp pictures. It is worthless without all three disks. There is a different kind of softness with each and with different lens openings.
The 180 is just a sharp lens like the millions of others out there.