I like many in my age demographic was spanked as a child. I could tell though that my father struggled with doing it, he really didn't want to and it was obvious he took no pleasure in it. I think he just didn't know what else to do as far as disciplining.
I don't know how it affected me personally, except I don't spank my own kids. I just can't do it. Perhaps I'm like my father after all, but now society has provided other methods for parents to choose from.