I was never precepted by a PA or a midlevel at Duke except on my OB rotation where my primary preceptors where the exceptionally talented Nurse-midwives. These ladies know a lot about pregnancy and childbirth and it was my privelege to be instructed and guided by them.
But the Family medicine clinic had a lot of very competent mid-levels seeing their own panel of patients and more-or-less functioning as family physicians. They did precept medical students but never the residents as I suppose this would have caused a riot. It is fashionable to pretend that prestige is not important to physicians but, to paraphrase Dr. Evil, a lot of people, "didn't go to four years of evil medical school to work under PAs."
I am a big fan of PAs. I think it's a perfectly reasonable career choice and if they can do the work, then they should. This includes work in Family Medicine, Emergency Medicine, and other specialties. I also don't believe that PAs should be limited because they are encroaching on doctor's turf. I've been against that kind of protectionism in every aspect of economics and I'd be a hypocrite to all of sudden cry "foul" when it's my ox being gored.
On the other hand it is also fashionable for mid-levels to believe that they know as much as physicians which is not the case. Clearly a PA who has been in practice for ten years knows more about practical patient care than a newly minted intern. That's just experience. But there is no comparrison to the level of knowledge between a physicians who has just finished his training (from seven to ten years worth of it) and a PA who has has just finished his.
The fear for young medical students and residents is that they have wasted their time struggling through their training when somebody with a third as much of it can do their job as well...and more importantly that the bargain hunting public and the government sees it like this as well.
The Duke model of family medicine, by the way, embraces the mid-level providor at the expense of most of the physicians. Please read the article on my humble blog on this subject.