It hurts more or worse on different parts of your skin... depending how sensitive your skin is.
My doc gave me a topical numbing cream, which takes some of the edge off. Take a dose of advil about an hour before.
They should put aloe gel on the skin during treatment, and cortaid cream after.
The pain went away in under an hour for me, I was hardly red at all (and I have VERY sensitive skin!)
I would definitely have it done in a doctors office, even though a tech will probly do it, at least it will be a safe, clean environment, under medical supervision. Those laser factories are scary, and I would worry about how safe they are...