Up All Night, I thought I'd comment as a lone (so far) voice of someone who hasn't had surgery... yet. I have recently struggled with the same stuff you have. I have a 4 cm probable AN in the CPA. I found out about it in January. I'm pretty much asymptomatic (fullness in one ear, normal hearing and everything else), and like you I've often wondered if I could wait a bit longer, keep my hearing a bit longer, etc. I'm 34, so the age thing was a factor in that, too -- "I'm too young to lose half my hearing," that kind of thing. And perhaps like you, I have an instinctual disinclination to get surgery. I've never been hospitalized and brain surgery seems like a helluva way to break that particular streak.
I took some time after diagnosis to take care of some other stuff (important work milestone) before turning back to my tumor. Since then, I've thought a lot about this and done a lot of research. I've decided to get the surgery now. There are a few reasons for this. Most significantly, the medical literature is clear on the fact that functions lost are more likely to stay lost or get worse after AN surgery. So even though my facial function is fine, I would be decreasing my chances of having full function after the surgery if I waited for that function to degrade before going under the knife.
Other complications can arise, too -- hydrocephalus, brain stem compression accompanied by increased difficulty of surgically separating the tumor from the brainstem, and other things people in this thread have alluded to. There's also the non-zero (yes, very, very small but still there!) chance of rapid tumor growth in certain situations, and these tumors aren't too accessible on an emergency basis.
So all in all, I completely understand your reticence for getting surgery. I would say there are some very good reasons to get it, though.
Good luck in figuring this all out.