Personally, I never understood the fuss around 400TX while the 320TXP run circles around it, literally. It was and still is my favourite overall B&W film, point period. Whether it's darkroom enlarging or scanning the Tri-X 320 (320TXP - the proper Pan) is just heads and shoulders above the common and vasty overhyped Tri-X 400 (400TX) that looks rather tonally "gutless" and "sterile" in comparison IMHO. Ironically the 400TX somehow managed to get "critical mass" of hype while the vastly better (IMO) 320 version that has better dynamic range, more shadow and highlight info, less grain and also much nicer-looking grain was always little known and not so widely available.
And look what's happening now - 400TX is still produced while 320TXP got dropped by Kodak and ironically never was advertised like the limited 400 version - (probably the cost of producing the 400 was less than 320 thus it ment less profit?)
Anyways, this particuar Tri-X case definitely proves we live in a (over)hype-based society where a simple practice or just common sense has very little relevance on what's being produced.
For me the Tri-X is long dead (after the mighty 320 was discontinued by Kodak). I have a couple of rolls of 320TXP left and I value them as pure gold while the occasional couple of rolls ot 400TX (ASA1600 diafine is usable for some applications) I have is worth like the usual copper in comparison for me.