My former residency program would trip over themselves when we had an application from one of the Ivys. The 2 most memorable "Duds: were from Hopkins and UCSF. Both had personality issues.
I love it when writing a LOR for one of my students that I can mention that they are in the top third or even better, top 10%. It will be noticed by PDs. If they are in the bottom third, I dont mention class rank. If in the bottom half, to mention it I would try to note an upward trend. P/F would not allow me to do this
Many schools have very subjective grading for clinical rotations, I think P/F is helpful as there can be wide variability in clinical grades. Graded clinical rotations might not reflect the students performance accurately.