Both films are very good for portraits, IMHO. They have somewhat different looks even apart from grain differences, but either should be okay. If you're doing small enlargements (5x7s), using a medium format camera, or have limited lighting, Tri-X is the way to go. If you're making 8x10s or larger from 35mm negatives, Plus-X may be a better a choice. (Also consider Agfapan APX 100 - it has finer grain than PX and yields a unique "glow" on Caucasian skintones that's very lovely. I haven't used APX 400, but I think the consensus is that TX is a better choice at that speed. And then there are Ilford's old- tech films, FP4 Plus [125] and HP5 Plus [400], which are also excellent...)(posted 9292 days ago)Heck, you can do nice portraits on T-Max or Delta films too: it's more a matter of lighting, subject, background, camera/lens, developer, paper, etc., than film, although I personally prefer the look of old-tech films for portraits...