I too have been lucky to be able to use a university health service for primary care, prescriptions, lab work and x-rays, physio and specialists. Most things are all under one roof but I have had referrals to hospitals in the area (this being Boston they are all excellent) I also have very good dental insurance from the University.
Another problem I have with the American system of health insurance (medical and dental) is that I think it encourages practitioners to go overboard for tests/procedures -- because (if you're one of the lucky ones) you do have the insurance coverage. My doctor said she really didn't think it was necessary to get Pap smears, for example, every year but its covered so she does it.