Though Art Dudley disagrees with me, my number one priority is lifelike vocal and instrumental timbre---lack of what J. Gordon Holt called "vowel colorations". Next up is immediacy and presence---the illusion of living, breathing humans singing and/or playing right there in front of me, fully formed and fleshed-out. Too many systems I've heard create "whispy" (ghostly apparitions), miniaturized voices and instruments that sound thin and small, lacking body and substance. Live music sounds big and bold, I like it's reproduction to as well. Live music is experienced not through just the ears, but the entire body. Reproduced music often sounds eviscerated, robbed of it's physicality, appealing to the intellect only! That for me is the main failing of music reproduction systems, apparently even harder to achieve than the ability to provide lifelike vocal and instrumental timbre.
