I've just seen the results from my first ever roll of TMAX 400 (old one), processed in HC-110. I like it, but IMO it's nothing special. The grain neither adds character to the image nor annoys me or gets in the way. The apparent tonal range is excellent though.

I'm happy enough with it that I can use it up - a friend gave me around 15 expired rolls. I'm afraid I'm not experienced with Tri-X, but I hear it's close to HP5+, and I love that too.

Also, a thing that I found useful: when I was looking up the Kodak sheets for the development times, I saw that for HC-110 (B), it's recommended to expose TMAX 400 (TMY 5053) at EI320 rather than at 400. Just thought I'd point that out in case you're a HC-110 fan