vow, I was testing spidf out of my Vu solo, and indeed it's very poor,
I haven't noticed before, because I was using an old receiver, but when connecting to an external DAC and integrated, you can noticed it's very harsh practically unlistenable, I tried different high quality cables,
but when using TV digital out (connected to vusolo by hdmi) to external DAC, sound is much better, means that vu+ hdmi out is ok, only spidf is affected,
this is only about sound quality, I have no audio drop outs or else,
no wonder nobody notice it, I did it only on a pretty good revealing audio system,