its a nice film. but with some drawbacks IMO.
1. Its more of a "straigt line" film than the original 320-speed tri-x, the 320 tends to taper off at the shoulder(highlights), helping to keep the highlights from blowing out.
TX400 tends to blow out the highlights, rather than retain the details that are generally wanted by most. Obviously, testing is the best way to assess what film speed needs to be used in order to give you enough shadow detail(if you want shadow detail that is), but still retaining highlight info.
Personally, I prefer 320TXP in 120/220 and 4x5, but I've been finding myself shooting more TMAX 400(TMY-2) lately. Its a great film, very "straight line", but with great contrast in the highlights, along with great tonal separation in shadows and highlights. When done right though, as with ANY film/developer combo.
for 35mm though, I've been shooting primarily Tri-X lately, primarily due to it being cheaper than TMAX 400 in 35mm. I don't enlarge very much(generally less than 8x10 90% of the time)
give it a shot though. lots of people love TX400, and I highly doubt its going anywhere anytime soon.