I feel sorry for Dan. I don't think anyone really understood or even read his post. If you can understand how a Digital to Analog Converter works, you'd understand how absurd the idea of a truly non oversampling DAC is.
He was merely trying to explain that a NOS DAC that contained an analog filter would be an inferior piece of equipment, and this is likely the case. Some NOS DAC's ignore the filter entirely, leaving it to the listeners ears to filter the music. Dan made a very technical and concise explanation, and I believe that people should at least read through his statement and come up with a technical refutation as to why NOS DAC's are better than oversampling ones, before saying that he's just trying to protect his business.
Also, a lot of Digital to Analog Converters that are marketed as being non oversampling are not actually non oversampling. Chances are, more than a few people on these forums who think they have a NOS DAC don't actually have one. Again, this is because many consumers don't understand what their DAC is actually doing with the digital signal, and just believe what the seller is telling them.
But don't believe what I'm saying either, just look it up for yourself. This is a decent place to start.
Upsampling vs. Oversampling for Digital Audio — Reviews and News from Audioholics