Here, in Poland Ilfordpan400 is twice as cheap as HP5+.
There were some discussions about Pan400vsHP5+ on Polish newsgroups and if I remember well, most people found no big difference between them. Some claim that Pan400 might be HP5 and Pan100- FP4, but nobody knows it for sure. AFAIR, HP5+ emulsion was different colour from Pan400.
I used Pan 400 from Slovenija side by side with bulk loaded HP5+ and could find no difference, the HP5+ was close to expiry and the Pan 400 rather fresh. Comparing Pan 100 to FP4+ both close to expire date, I found the Pan 100 to be more grainny, so could be old FP4 emulsion.
An Ilford employee (he's no longer employed there) told me that pan 400 is HP5+ and pan 100 is FP4+. He claimed that they are cut from the edges of the roll (the film is made in big rolls, then cut in narrower sizes), which are considered to having more flows (marks, etc) than the middle part.
An Ilford employee (he's no longer employed there) told me that pan 400 is HP5+ and pan 100 is FP4+. He claimed that they are cut from the edges of the roll (the film is made in big rolls, then cut in narrower sizes), which are considered to having more flows (marks, etc) than the middle part.