It's a fantastic portrait lens if you shoot it wide-open. The Dagors have aberrations that will give some subtle glow/diffusion to highlights when shot wide-open -- not quite as pronounced or obvious as what you see in Hurrell's Hollywood publicity photos, but enough to make a pleasing difference. I've shot an early 7-inch Dagor in 4x5 and 5x7, and love the results. (I shot my APUG avatar image with that lens, mounted on a 5x7 Deardorff. Go to
www.mcnew.net for a larger version of the photograph.)
The Dagors are sharp, and you need their sharpness for the eyes in portraiture. But if you shoot it wide-open, and focus on the eyes, the limited depth of field combined with the highlight diffusion will soften it plenty for your needs away from the eyes.
I would not shoot the Dagor as a single cell. I've gone that route, and I was disappointed with its performance. To get respectable results with the single cell, you need to stop it way down. Otherwise the results are unacceptably muddy to my eye.
Sanders