Tom Hoskinson wrote: "Delta 100 does not respond well to N+ and N- development. If you are into that mode of photography, you would be happier with Ilford FP4 or Efke 100 IMO."
Hi Tom, I agree that Efke 100 and FP4+ are nice films, but I'm surprised that you have not found Delta 100 responsive. I really don't use Delta 100 too much any more, but I used it extensively a few years ago. In Xtol, D-76 and Pyrocat HD I was able to get negatives for which ever process I was planning: conventional silver printing, or any of the alt process I do (Albumen, Van Dyke, Kallitype and Pt/Pd.)
I have a 30x40 print that was made from a Xtol developed 4x5 Delta 100 negative. Everyone that sees it is amazed by it, because it has the complete range of tones, wonderful shadow & highlight (snow) detail and you can put your nose to the print and there is no hint of grain.
Delta 100 is a very nice film, don't hesitate using it.