In 35mm format, NP400 has beautiful highlight detail compared to HP5+.
NP400 is very near the complete film, it has great shadow detail and the highlight detail is superb. If exposed and developed carefully, it is a wonderful film.
I have close to 300 rolls of NP400 in my refrigerator!
I develop it in D76 1+1 rotary.
With my system for general use, I rate it at 320 ASA, under tungsten it requires more exposure and either 250 ASA or maybe 200 ASA is about right.
FP4+ is a wonderful film which I also use a lot of, NP400 is a lot like FP4+