Without the risk of further controversy, there are different DAC technologies to Delta-Sigma.
Some vendors use R2R Ladder DACs (with and without Oversampling), some use FPGA based solutions.
Everyone’s noise environment is going to be different, because everyone’s configuration, environment and setup is different, and therefore the application of different technologies, solutions will have different effects. And at the end of the day,we have to listen to these systems to make the final assessment.