Small world. My AN was also 3.5 cm and I had also lost most of my hearing before surgery on that side(left). Dr. Chang was very forthright in explaining all the risks, but he was also confident that I'd come thru it ok(which I did). There was a fair chance that I'd come out of the surgery with facial weakness or some facial paralysis. However, I had only slight facial weakness. My biggest issue post surgery was my eye on the AN side. Because I had some temporary facial weakness, my eye didn't blink that well and I needed to keep it lubricated all the time. This got much better after about 3 months. Today, I still don't produce tears in that eye, but I only have to use eye drops a couple of times a day. The only other thing I have is tinnitus on the AN side, but I've learned how to block this out most of the time.
As far as recovery after surgery, mine was pretty good. I had surgery on a Monday and went home that Wednesday morning. Friday of that week, I started walking around the neighborhood. At about 3 weeks I started running again(2 or 3 miles). I went back to work for half days a month after the surgery...did that for a couple of weeks before returning back to full days. I work in an office and commute about 30 miles each way. I did notice my concentration level wasn't quite the same in the beginning, but I'd say after about 8 weeks, I was pretty much all the way back on the focus and concentration level.
I don't want to make any of this sound easy, because it's not....but having a positive attitude and great doctors(like Chang) will go a long ways towards your recovery and back to normal life. Like Brenda stated, it would also be good for you to attend the support group meeting here in Houston in November. You can learn a lot from the guest speaker(s) and other people that have been through this.
Also, I'm not sure which neurosurgeon Dr. Chang is working with these days, as the one that teamed with him on my surgery has moved to Denver. If you don't know this, you should find out who the neurosurgeon will be and also go talk to him/her about his/her experience with AN surgeries. I always made a list of questions to ask at each doctor appt. If you can, take somebody with you for your discussions with the doctors...my wife was invaluable support to me for this as I would not necessarily remember everything that was said.
If there's anything else I can help with, let me know.