ES File Explorer does a lot, and I do mean a lot of stuff well, however FTP is not one of them. The ability to turn your phone into an FTP server to manage local files by connecting your phone and laptop does add a certain value but still does not equal to an Internet wide FTP client. It does allow access to the cloud via retail programs such as Sugarsync but not as a true FTP client.
It is obvious from the name ES File Explorer that it was designed to be a File explorer program and it does that extremely well and it has a host of other great features that are beyond the scope of this review. That being said as a standalone FTP client used daily to upload and download files it really only accomplishes download. If you are looking for a fully functional FTP client, ES File Explorer should be near the bottom of the list.