Have not, but as a Cambridge, MA resident I felt compelled to weigh in :). My husband and I use Harvard Vanguard and have been extremely satisfied with the care. Everything is integrated across specialties and their charting is electronic, so you don't have to recite your medical history every time you go in. They're also great about making same day appointments and we've liked all of the doctors we've seen. Plus, they have on-site pharmacy, phlebotomy, and other great stuff that I can't think of. And, did I mention the multiple locations? They have multiple locations, which is super handy.