I used a 160CB, which was on loan to me for about 8 months. I hated the bokeh and the OOF areas. The sharpness of the Tessar formation is decent at a smaller stop, but at 4.8, hair isn't displayed as sharp as it could on high key backgrounds.
With my 150, the sharpness is actually higher, and the lens is a bit more compact. Plus, the bokeh is a bunch more smoother than on the 160CB.
The 180 is the sharpest lens in the area, maybe too sharp & requiring a softar. The 180 is heavy as hell (compared to the 150). I shoot a lot of portraits (B&W & Color) and I do a ton of weddings too. The 150 is the best lens to use. Combine it with a tube 16 and you've got it made.
If you want the best for linear sharpness, color sharpness, and color quality, the 250SA is the ultimate lens!
I'd actually rather have a 150CF than the 160CB (that's after having both and shooting extensively with both)