Since I gave up bulk loading as too much PITA for the savings even at the old prices I don't much care - I'll keep using Tri-X when the combo suits.
I did try HP5, may have been without the plus, in it years ago. I don't recall details except that it worked well but got a stop less effective speed. Box (the Diafine box, not the film) speed for Tri-X was 1600 and for HP5 IIRC 800 and those were pretty good. Of course modern Tri-X seems to give me less, at least with tungsten light. I can use 1600 fine with daylight, say a heavy overcast day, but under tungsten I need more like EI 1000 so the difference now may be effectively less if HP5+ still responds like it did then. Or perhaps I'm just much pickier now.