Andrew,
Compliments on your approach! It seems you're already started down the road towards making a good decision for yourself.
I was diagnosed in August with a 3cm right AN. I did the research, talked to the docs, and decided that surgery was my best option, particularly because my tumor is starting to press against my brainstem. I'm having the AN removed via translab on November 7th, here in Las Vegas.
Personally, I would take your approach, given your tumor size. If you aren't experiencing too many symptoms, or they aren't bothering you, then waiting and watching makes sense. However, I might request my follow-up MRI a little sooner, something like six months from now. As you read through this website, you'll find numerous instances where tumor growth occured very rapidly - you'll want to stay on top of things on a regular basis.
If the tumor grows, or your symptoms worsen, then it's time to figure out your best treatment option. I decided that radiosurgery wasn't for me, although I did find information that even my large AN could be treated with radiation. You'll have to find the solution that's best for you. Do the research (try the House Ear Clinic's website for info on surgery, and try the University of Pittsburgh's site on information about radiosurgery, for starters), talk to specialists and both, and choose what makes you the most comfortable. There are risks either way, but remember: the procedure is truly saving your life.
My hope is that you can watch and wait until you're 100 years old. However, I would starting getting prepared for other options now, so that you're not scrambling later.
Good luck, and please keep us posted!
Josh