This is retrospective for me, but I'll still respond.
My main purpose in getting the surgery was to correct functional issues, in the sense that if my bite did not pose a functional problem I wouldn't have gotten the surgery.
HOWEVER. I was looking forward to the surgery intensely and the reason for this was the aesthetic change. I was very self conscious of my underbite.
I figured I wouldn't look too different, but I had no idea what I would look like.