While I agree with the sentiment that simpler is better, this is referring to discrete chips being used in a stacked manner, rather than the configuration of an integrated single chip with a documented use case for parallelisation. However the ONLY advantages of stacking a Sabre DAC is improvement to SNR (3dB each time you double the number of DACs, so a total of 6dB for 4 DACs per channel), and a slight improvement to THD. However, while this can be measured, the counter argument is that it is inaudible because we are talking going from 110dB SNR to 116dB...can anyone really hear that? I am not attempting to answer the question by the way....just putting that question forward for debate.
The ES9018 has specs of 128dB SNR in 8 channel mode. 133dB in stereo mode. If 110dB is inaudible what would 128dB be?
It seems likely that the analog implementation is going to be what determines the sound quality. Stacking these DACs is likely to be a waste of money that could be better spent elsewhere in the design.