Does Spam Cop Work?

I have recently started a new email address and am already getting spam on it.

In times past I have checked the headers located the offending ISP and emailed the webmaster of the company it was sent from/through. This is a tedious process.

I was thinking of signing up with SpamCop for their free service. It appears that through using their service the amount of spam can decrease and if the spammers figure out you are a trouble maker they might drop your address from their lists.

Anyone reading this ever use SpamCop? Could you leave a few lines concerning your experience? Is there any downside to using their services? Besides time that is...
Does it work with email services like Yahoo and Gmail?