The sound seems to have a technical problem, below a certain frequency of sound is apparently converted directly into loud humming vibration of the entire housing. Otherwise, it is sufficient for language but film music is not fun.
The operation is still, as I know it from my childhood, completely designed for TV playback. Anyone with its truly numerous inputs actually wants to use only for BluRay, Streaming, Chromecast, computer games, etc. the device is nevertheless constantly find again in the not furnished TV programs. Accordingly, the program selection buttons are gigantic, while never take the tiny Play / Pause / Stop buttons in the dark. CEC, control other devices via the remote control, also has the Macke, with each change of the input to forget the pairing. Standby and automatic switch whose signal does not work, at least not as you know it from displays for the computer. Want to leave the power to the unit but eh not, because then all the time has a lighted lettering in the room, the only kindly dimmed in several stages (!) Leaves. The reaction speed of the device is slow, you're at the turning, menu operation or signal source change.
The whole Smart TV functionality can be described at best as nonsense, hard to use and applications, there is only a minimalist house download area. DLNA is so reasonably. Video streaming from Amazon is not supported and the restrictions on both sides ensure that one can not upgrade it. The same applies to AirPlay, Chromecast and similar services that could possibly be ported to a more open platform.
Conclusion: The Grundig is an affordable device with very good 2D display. As long as you do not too much of the sound and expects to 3D and Smart TV functionality makes a bow, you can be very satisfied with what you get for your money.