It was then, unfortunately.
Miracast / WiFi Direct
I have tested it with 2 devices to eliminate errors in the transmission hardware (Nexus 5 & 7). The dongle I have specially placed in the front-HDMI with my AV receiver, so that as little distance / obstacles are in between.
The connection worked still pretty fast. After about 30 seconds was the picture on the monitor. However, the problems began immediately afterwards. Even if I wanted to transfer music, was at a linear distance! of about 50 cm final. Youtube videos via Miracast the dongle? A maximum of 10 cm next. And that's now wirelessly?
The Miracast functionality of the device is just a disaster and can not be used. TV's with built-in receiver go over at least 1-2 m in music even without problems for more than 40 euros to sell something like this here I feel almost as an insult.
DLNA & UPnP
Good, I thought. Miracast not the point. Perhaps I can serve as a DLNA receiver that thing then at least.
Downloading videos from the local network lasted ever for ages. I would not cope, would be at least the sound of the video signal in the original 5.1. No, because you get a stereo mix at the plant. This can be any DLNA dongle better and is cheaper.
Conclusion
I think the seller should really consider to have as an immature and it still fairly expensive product on offer. Now I have to pay 2x Shipping, for a small particle electronic waste ...
Oh, and to all Security Fans: The default password is preset with the dongle 12345678, that's even nice :)