the first CD players were so good already that all those improvements are just on paper. All CD players sound flawless and always have.
Some were good, some weren't so good. I can point to a few examples why some earlier players had problems. As far as DAC prices dropping exponentially, well, DAC's have never been nor are now terribly expensive. As time has gone on, one thing we've seen is the ability of DAC's to play different formats like mp3's, CDR's, the plus and minus variants, incorporation within the DAC to do different things, and all that good stuff. I guess, in a sense, you can interpret increased functionality as 'prices dropping'. Personally, I don't happen to think that audio reproduction attracts our best talents.