Yes it is worth. And yes, we can use normal AV cable to connect SPDIF.
Till now I didn't face any issue in the decoding and I am getting actual 5.1 surround sound for all HD channels and also from my Blue Ray player.
It can also simulate 5.1 for Stereo input (i.e. for SD channels or music CDs). I am facing one issue here only (but very rare). Suddenly the audio will be lower in front and high in the rear only for stereo. To get this solved, I used to change to a HD channel and then back to SD channel. This is a very rare scenario on selective channels and selective type of audio in the channel.
We also have a switch to have the output in 5.1 or 2.1. We will not face the above said problem in 2.1 for SD channels. Also, to solve the problem, instead of switching channels, you switch to 2.1 and then again to 5.1.
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