I had a spinal when I had knee surgery. I was pregnant with DS #1, so they didn't want to put me under.
I did not have any problems. It was actually kind of cool being able to see what the doctor was talking about. He was able to show me what my problem was right there and tell me what he was doing. He even gave me the option of fixing something that he didn't anticipate - as in fix it now or come back in 6 - 9 months after I delivered. I don't regret it at all.
For me, they gave me some medicine that made me feel like I was having an out of body experience. I watched the whole thing on the video screen, but it was like I was watching something on TLC. It wasn't scary or gross at all. And I couldn't feel a thing. I did not have any side effects from the spinal after surgery. I have heard that it is possible that you could get a blinding headache for a while, but that didn't happen to me.
Good luck with your surgery.