Perfectly normal to be scared. I was terrified before my surgery!
I had surgery in Sept 2006 with McKenna and Barker. If Dr. Lee is in McKenna's office, too, I'm sure he's also excellent though I have no personal experience with him. You're in the hands of some very skilled surgeons. I wasn't too impressed with Dr. Barker's office persona but, quite frankly, that wasn't my primary concern when picking a neurosurgeon! LOL!
At the time of surgery, my AN was 2.3cm. I came through surgery (11 hours) with flying colors and have no lingering issues - other than being deaf on that side, which was a known outcome of translab surgery. One of the things that impressed me about MGH was that they have anesthesiologists who only do neuro surgeries (quite a sub-specialty!) and they had developed specialized protocols for how to best manage anesthesia for AN patients. To me, that says they have all the right experience.
Please ask if you have any specific questions. Many of us have been exactly where you are and completely understand the whirlwind that's going on.