When I was pregnant and house-hunting, an estate agent tried to sell me on Sebastian for a possible son: she found it very distinguished. But, she was originally from Italy, and I had to point out that in South Africa at that time, Sebastian didn't really happen in English, and in Afrikaans it was stereotypically the opposite of sophisticated: more like an unemployed man selling the vegetables he grew in the back yard and sepending the takings on beer.
So the answer is, it depends on where you are.