Can't speak to the Sony models at hand, but I just upgraded from a really cheap Sony BDS-P3700 to a hundred dollar BDS-P6700, and the improvement in visual and especially audio quality is immense, despite the two units having largely identical advertised specs. This is going into a Onkyo TX-NR828. For concerts where I have both blu-ray and CD, the CDs still sound ever so slightly better played in an Emotiva ERC-3, but that's up to the DAC in the ERC-3 being better than the DAC in the Onkyo. So at least on Sony player is excellent despite the price; and at least one other is as cheap as you'd expect all around.