SSL proxies offer two huge advantages, both of which stem from encryption. They are generally safer and more anonymous.
1. The proxy is more secure -- the SSL layer provides encryption between the requester and the target server. This layer protects your information from third parties, such as Internet service providers (ISPs), hackers, or government agencies. Even if an outlaw manages to successfully intercept or monitor your connection through a proxy server, it will still be encrypted using the HTTPS protocol, not HTTP.
2. Be anonymous -- The proxy hides your IP, but the additional security of the SSL layer increases your anonymity because it reduces the information available about your connection request.