I still think it's the best 400 speed b/w film around. It just works and looks gorgeous.
Although I have to admit that I'm very impressed with TMY-2 400. But it does have a different look, so it really is a matter of taste.
Here is a quote from Wikipedia:
"Tri-X is a classic high-speed black-and-white photographic film from Kodak. Introduced around 1940 in sheets rated at ASA daylight 200 and tungsten 160, it was one of Kodak's first high-speed (for the time) black-and-white films. Tri-X was released in 35mm and 120 in 1954. Currently it is available in two speeds, ISO 320/26° (320TXP) and 400/27° (400TX). Tri-X 400 is the more common of the two, available in 24 and 36 exposure rolls of 35 mm and 120 as well as 50 and 100 ft bulk rolls of 35mm. Tri-X 320 is available in 4×5", 5×7", and 8×10" sheets."