This Foma 400 sure does cause different reactions in different folks, doesn't it???
I like it . . . it produces it's own "look" and is responsive to different developers. Quite versatile, really. It's now my second film when I want a different look or feel to HP5.
Here is Foma 400 in Rodinal, 1:50, 12 minutes, Half-Frame negatives from an Olympus Pen FT (print scans)
And here is a scanned print from a full-frame negative (Pentax MX) in Xtol - quite a different look: (this print was also brown toned, but look not at that, but the grain structure and tonal graduation differences to those above.)
I'm looking forward to developing my first roll of Foma 200, which is in a Nikon FM from my collection right now. But I will certainly be using Foma 400 any time I want small neg impact. Love it!
Bright light and contrasty subject matter, Xtol. Flat lighting and less contrasty subject matter, Rodinal. There might be other "looks" but I tend to use certain films for certain looks based on my own experience. This is what I've come up with for Foma 400, and it works for me.