I can now officially say that I've shot Tri-x everywhere from ISO 200 all the way up to 3200. I tried 6400 once and got viewable if not completely acceptable results. Most of these shots are just for test purposes. I just wanted to see how well it would hold in the highlights and shadows if I overexposed. I would say it fared pretty well in that area.
Developed in d-76 1:1 for 9:15. Development details on FilmDev