To my taste, one of the great virtues of Efke 25/CHS 25 was its "orthopanchromatic" response, with reduced red sensitivity compared to a true pan film. It gives portraiture a little bit of the "grit" of ortho film, but it's moderated by the extremely fine grain and a general smooth-and-creamy look, and when the stars are right that combination can really make the subject pop in an environmental portrait.
The other nice thing is that it doesn't build contrast particularly fast. Ortho films like the Maco/Rollei ORT25 tend to, and of course CMS 20 actually requires a special developer to keep the contrast under control. I have the idea that Pan F+ tends to high contrast, right? Do people have tricks for reining it in in that respect?
Thanks
-NT