Some like it, some don't, personally I don't. It is true about a drop in speed but this will happen with virtually any service that hides your IP.
I used it for a while and the biggest pain I noticed was how long it took sometimes to connect.
Cyber Ghost is pretty much like a VPN that lets you reach blocked web sites that are either blocked by your ISP or government, just like most of us in the U.S. cannot reach certain torrent or download sites, Cyber Ghost or virtually any VPN service will allow you to circumnavigate that problem and reach those sites by masking your IP address to make it look as though you are coming in from another country that allows access to that site.
IMO, there are Free VPN services out there that do a much better job than Cyber Ghost, personally I recommend SoftEther which you can find here >
SoftEther VPN Project - SoftEther VPN Project