The new 400TX looks very similar to the old TX, maybe a little smoother and finer grained. I don't have any experience with TXP versus the new 320-Tri-X. My experience is that HP5+ is that it is quite different from any of the Kodak Tri-X films, although it is very roughly similar to the Tri-X of about 10 - 15 years ago. (Not really the same look at all, but that is the closest, IMO) HP5+ is a fine film, and it is very consistent from batch to batch and format to format, but it is different from Tri-X. Although D-76 has not changed, the films may respond differently as they change. Considerable manipulation is possible with D-76, and small changes in technique can result in considerable changes to the look of the negatives.