No one location is better over another. Yes, HEI does a majority of AN removals, yet..... here on the east coast, Boston has a medical mecca with Mass Gen Hospital/Mass Eye and Ear (MGH/MEEI) as well as Brigham/Womans, Tufts Medical and Beth Israel Deaconess, as many on these forums can attest.
Clarice notes that many factors need to be taken into consideration: location/size of tumor, does your insurance cover for you to travel out of state, experience of treating physicians, patient referrals (as you are gathering here), but a major key factor... if you travel for AN treatment, then travel back home, who will do your follow up care since you will not be near the surgeons? That is a major factor as it is the post-surgical follow up that will be key.
No one place is better than another.... but please keep these factors in mind when determining a treating physician, regardless if surgical or radiation.
Phyl