I haven't used HP5 for many years but I LOVE TriX. Versatile, Great tonal range, it responds well to development changes. 400 is an excellent speed, especially if you favor using filters and handholding, and it pushes and pulls beautifully. Not to mention the pure tradition of it. I'm sure that it was the first B&W film that I ever shot and it was also the last (yesterday). I always have at least one, and usually a couple of bodies loaded with it.
If that disappeared, I'd go into mourning.