While no two situations are identical, doctors estimated my AN had been growing for 15 to 20 years by the time I had symptoms sufficiently bad to warrant a diagnosing MRI.
The mass effect on both my cerebellum and brain stem were significant and my fourth ventricle had shifted from the brain compression. I was given 5 to 6 weeks to have it removed.
I had surgery Oct, 2011 and 95 - 97% of the tumor was removed. One year later the follow up MRI showed stable size for the tumor and no remaining mass effect on either of the parts of my brain that were previously compressed by the tumor.
I had problems with my balance and orientation for 7 months following surgery and now experience only occasional, momentary periods of feeling "off." I now consider my balance better than before surgery. That said, I was walking outside a few days after discharge. I was OK'd to start jogging at 3 months, but it still took 7 months to improve completely.
Because I had a large tumor, my lower cranial nerves were involved and dissection of the tumor from them resulted in vocal cord and swallowing problems that began to improve in about 8 months. Today I am about 90% normal in both areas.
My hearing is gone completely. Being SSD - Single Sided Deaf - has not been a major problem for me and I have adjusted to it.
All in all, after 18 months following surgery, I consider myself close to normal, or close to how I was prior to surgery. Good luck.