I would just add that until the surgeon's are actually in there, they make no guarantees. They knew my tumor was not invading the auditory canal and said they thought they could save my hearing but still no guarantees. Surgery was really my only option. My tumor was not small, so I figured as long as I came out alive, I would do my best to deal with whatever side effects I was left with. As a musician my hearing is especially dear to me but I was willing to sacrifice it if that's what it took. Like many of, us, I feel my doctors were superb and so was the standard of care I received at University Hospitals. I had two surgeons, for whom this type of tumor was their specialty, who also have done so many of these surgeries.
It sounds as if you have been very fortunate in finding doctors that you like and in the decision making process. Regarding BrainLab, someone on this site has spoken of it before so if you just search for it you may get more information. Again, no matter what you choose, experience and success rate in your doctors is paramount.
Good luck with all,