It is important that the mirror is connected to a Gigabit LAN port, as should the / the computer be connected to such a. It is also important that the NAS assigned a fixed IP address on the router. Taking into these points, you should be able to exploit the full power. The subsequent test in terms of reading and writing rate was absolutely good values (50-60 MB Write / sec and read 80-100MB). After all, writes and reads the device faster than the good old USB 2.0 external hard drives. The initial Time Machine backup will take as usual a bit longer (depending on the volume of data - with me about 2 hours). However, this is due to the Time Machine software, not the NAS.
Visually, the device is completely living room compatible (I personally like a lot better than the more or less identical EX2 in Black). You can also ask why in living rooms, since one perceives them as good as not in operation. Only the flashing LEDs can irritate some, but these can be switched off in the menu.
And now I come briefly to the scope of my WD My Cloud Mirror. I set the device actually only for backup (Time Machine backup) and as a network resource. The media server I do not really, but I use my Apple TV, which is why I have the DLNA disabled. Den from anywhere accessible cloud service I have also turned off since it makes little sense, because although I have more than to wish a brisk internet access with 30Mbit / sec download, but unfortunately leaves the offered by the ISP upload with 2Mbit / sec left (a silent call to any ISP, finally time to upload speed to the 21 century. adjust).
Conclusion, the My Cloud Mirror is easy to setup and use, fast, quiet and provides more than I really need. The price / performance ratio is also absolutely unbeatable.