Have you tried a 4 second reset and or a 40 second system restore? Sometimes that solves certain issues with eh My Cloud.
http://support.wdc.com/KnowledgeBase/answer.aspx?ID=10432
Have you read the My Cloud User Manual (http://www.wdc.com/wdproducts/library/?id=439&type=25) which explains how to setup the device and use the various features/options?
How are you determining that the My Cloud is slow or that copying is slow?
How is your network configured? Is the computer your copying the files from connected via WiFi?
See the following thread that explains some issues with copying speed.
At the end of the day there are a variety of things that can cause the My Cloud to be sluggish/unresponsive or can cause slow copying speeds. The My Cloud’s processor/RAM is not very powerful so the unit will be sluggish if it performs too many actions at once. One’s network environment, computer connection to that network, the speed of the hard drive on the computer where the data is being copied from can all affect copying speed. And one almost never, ever gets the top rated speed of their network equipment. Typically one’s network speed is less, sometimes much less, than what the equipment is marketed as.
