My testing is for the TX 400. But my results are merely a starting point.

I just find that 11 minutes is a wayyy long. Even at 7.5 minutes my highlights were blown out of proportion.

I'm shooting at ISO 160 for Zone I though. So if you're shooting at a higher ISO, your development time is bound to increase. Your shadows may night be secure but your highlights will come out fine.

Heres an image from Tri-X with effective speed 160, and developed in D-76 1:1 70F for 6.5 minutes: