I have and was surprised to find when I was not knowing which DAC and the levels were matched (this made the biggest difference IME) I couldn't reliable pick out which was which. I -could- hear the difference of some of the reconstruction filters on the dCS where they were switchable.Who here has ever actually done one or properly?
Placebo effect is the only scientific explanation why some people may hear differences between level matched DACs as long as the laws of physics aren't repealed