The results of the scanned films are a little bit surprising. The show was exposed at +2 stops. From the density characteristics of the film manufacturer this exposure allows to keep texture in the show and in the same time rendering the snow white.
As a conclusion the Tri-X has more contrast on the negative but with more fog density of the film base.
All in all the two emulsions are very similar although a more subtle gradation can be seen on the HP5 negative.
Usage wise I think that both are very good in normal situations although the scene chosen was quite challenging.