Most of my applicants put it on the application (it is a good thing, they know the tuition is now covered with no issues for four years...money always comes first!)
I have interviewed for our local medical school. As far as I know, no one on the committee has opposed HPSP or seen it as a factor in admissions-decisions.
Given the uncertainty in medical funding in our country at this time, HPSP makes sense. My only criticism of it is the interest rate allowed private lenders on a government-guaranteed loan: Often more than a mortgage.
If you are interested in this topic, read "The Healing of America" by T.R.Reid.
H. E. Butler III M.D., F.A.C.S.
Commander, U.S.N.R., Fleet Reserve
Former Lieutenant Colonel, U.S.A.R.
Instructor, Psychiatry, E.V.M.S.
HButler@postdotHarvarddotedu