Hi Brian,
I'm glad you found us here. I was diagnosed nearly six weeks ago and have spent that time reading, researching, and thinking. Like many here, I've spoken to docs across the country and usually received conflicting advice.
One thing most doctors have told me is that if I had a symptom now, I would likely have it later. In other words, if I chose microsurgery or radiosurgery, I would likely have the same tinnitus post-treatment that I had before treatment. A doc I spoke with the other day said this was true with vertigo, too (or headaches).
If you don't have vertigo now, there's a good chance you won't have it later. Having said that, if you choose GK (what I've determined to do), when the tumor possibly enlarges post-treatment, it may induce vertigo. Similarly, the surgical procedures you chose could result in vertigo. I wish we were here to offer you guarantees, but there are none.
As you will consistently hear here, read, read, read and then make the best decision for you. I'm sorry you're facing this challenge at your age. But I'm also glad you "caught" your AN before it got even larger and you became more symptomatic. Some may advise watch and wait--another consideration--but it's all up to you. That's both comforting and distressing, I know.
We are here to help and support!
P.