I don't really like refurbished anything. My sister had a bad experience with a refurbished laptop and it makes me leery of that kind of thing. Also, I'm not sure that I'd like a "used" vacuum anyway. I like knowing the dirt in there is only from my house, you know? Maybe I'm weird.
I actually was just debating this! I ended up going with a new Dyson DC44- it's a cordless vac. This is why I signed up for Amazon prime. I looked into the refurbished one, but a lot of the reviews said it was dirty and still had dog hair and stuff in it. The cost savings didn't seem worth it to me.