Hi Simon,
I was in a similar situation as you when I was diagnosed: 31 years old, 2.9cm AN, young child, some hearing loss and balance issues.
Deciding between surgery and radiation was one of the most difficult decisions I've ever made. It took about three months and multiple consultations to get to a place where I knew in my gut what was best. My consultations included the original ENT, Dr. Thompson (neurosurgeon at U. Michigan), Dr. Slattery (surgeon at House Clinic), Dr. Steven Chang (CK radiosurgeon at Stanford), and Dr. Lunsford (GK radiosurgeon at UPMC). I also went on pubmed/google scholar and read a lot of published data on surgery and radiation outcomes. I ultimately decided to have GK at UPMC with Dr. Lunsford, and I still feel this was the very best for for me.
Why doesn't everyone get radiation? In my opinion every AN patient is different (age, co-morbid health conditions, tumor characteristics), and everyone has their own perspective on the risks and benefits of different procedures. I also wonder if access to information prevents a subset of AN patients from considering radiation. In any case, radiation use for ANs continues to increase, and both are considered viable options for many patients. For me, time and talking with lots of renown doctors with different backgrounds was essential for sorting through the confusion.
Good luck in your decision making and please PM me if you'd like to talk further.