HP5 is a great film. I like it better than Tri-X at 400. Tri-X is more pushable, though.
I get better staining with PMK with HP5 also. I get more dramatic staining on Tri-X, but much worse general stain which is basically like fog. HP5 stains much more cleanly.
Still, if HP5 disappeared I could more than live with Tri-X - and vice versa.