Pan-X was ASA 32. TMY-2 is ISO 400. They wouldn't be remotely interchangeable. Sure, if you had sufficient studio light for the Pan-X that you could, as needed, tone down for TMY you could do it, but a better comparison would be Pan F+, APX 25 if it were still around, Efke 25 (ditto) or even the new tech 100 speed films, TMX, Delta 100 or Acros.
Fair enough, I wasn't talking grain though I just meant overall look and my personal ability to expose them right