As Ilfordfan, I'd have thought the answer is obvious
On a more serious note DD will do as good a job with either film. For 40 years I bought a washing powder called "White Tide " because I saw an advert where a "very geniune looking" executive behind a desk said that his company's washing machines performed best with White Tide" I only recently found out that the executive was not an executive of the company making my washing machine at all but was an actor, paid to say what he had said. I was shocked
. You will be pleased to know that I have now manged to get over this shock
Try both films in DD, have the prints marked HP5 or Tri-X by a friend on the back out of your sight and the see if you can separate the prints accurately to a percentage figure that is statistically significant compared to chance
Let us know how the experiment goes
pentaxuser