A few points worth noting:
Back in April when John Marks mentioned the PS1, he said "For $25, it sounds wonderful." But added, "I am totally unsold on the claim of 'as good as $6000 audiophile CD players.'"
The unit used by Marks was an SCPH-1001, one of the good ones that was mentioned here. Marks did indicate though that his unit suffered from an audible disc spinning noise.
In the July issue, Atkinson measures his son's unit, a third generation SCPH-7501 and mentions that in most respects the measurements of the 7501 although it sounded good, were much worse than the 1001 Marks used and wonders, "if the 'magic' of the Playstation 1's sound lies not in it's technical excellence but in the fact that it smears over and disguises much of what is wrong with typical CD sound quality, to which it adds a touch of low-level compression from the linearity error."
The unit Art Dudley reviews is not the same one that Marks used, but it is also an SCPH-1001. He labels the PS1 as having "a very un-hi-fi sound." Dudley also says, "Partly because of my indifference to digitally mastered music, I admit to having less experience with cutting-edge CD players than do most of my colleagues." He mentions that if he had a $25k system (the Verdi La Scala transport and Delius DAC to be specific) he would happily trade it for a PS1. My impression is that to him, the PS1 has a sound that is less "digital" which is why he prefers it.