Neither of us had a problem with the age gap, my ex is intelligent and sensible, we just seemed on the same wavelength from when we first met. I would never have been attracted to some flighty airhead anyway.
Her family seemed fine with it as well. I always got on well with the her sister and parents, I was after all nearer the inlaw's age than my wife's.
Although it wasn't a major factor in our breakup it did have some bearing on when we wanted to have children.