The good -
The WD My Cloud EX4 offers data redundancy, Windows Server integration, and an excellent set of personal cloud features. It's also affordable and very easy to use.
The bad -
The server's write speed is disappointing. The mobile app supports a limited number of file formats, there's no search function, and it won't allow you to sort by content type.
The bottom line-
It's not the fastest NAS, nor does it include many advanced features, but the WD My Cloud EX4 still combines great ease of use into an affordable personal cloud system that's excellent for a connected home.