My hubby is nine years older than me. It isn't a very big gap, but it was enough to get plenty of negative reactions from his friends and family when they heard that he wanted to date me. My family were very accepting because my grandparents had a big age gap. It was also enough to get funny looks as we walked down the street and to overhear discussions about how we could be related because we couldn't possibly be 'together'.
The only time I notice the age gap is through the larger number of experiences he has had in his life. Though those occasions are rare because, although I am young, I do have some wisdom in me and (in his words) know automatically how a relationship is supposed to work without having much experience of it. He has dated older women who have not been the best partners.
There are a lot of prejudices out there about age-gap relationships and the people involved, but I always tell people we are with each other because we love each other and not because of how old the other is.