My neuro-ENT is at Mass Eye and Ear Infirmary. I don't know about Dr. Hadlock, since he's a different group, but MEEI is wonderful. I've not had an unpleasant experience there. And people come from all over the world (the first time I checked in, the family in front of us was from Bermuda) to see the physicians there. There's several of us New Englanders on this forum who go to MEEI.
It is a teaching hospital for Harvard Med School, so don't be surprised if you get observing tag-a-longs in your appt.
Good luck!
Katie