I've got a nice SACD player, and with the proper equipment and native SACDs, can hear the difference in soundstage and harmonics. I think most the population would hear differences if they were presented with it. But mp3 gained market share because of the convenience and copying abilities. At least now with storage always getting bigger, people transfer higher bit rate mp3s or FLAC audio formats. For high quality speakers, there's always been some issues of marketing: look how the lay public views Bose as a high end speaker product (no highs, no lows, must be Bose); or flabby bass headphones Beats Audio.
Exactly. Its all about convenience. My adult son is a professional musician and truly appreciates the high quality presentation of my $30K+ sound system, (which by today's standards is inexpensive). But he still does most of his listening through earbuds on his iPod. Its all about mobile convenience. We also live in a world where few people hear live music more then on rare occasions, and even then it mostly amplified. Most people are simply not educated and sophisticated listeners and don't care, For pretty much the same reasons, I believe the 6D Mark II will ultimately sell well because it will more than meet the needs, expectations, and skills of most people who will buy it.



