I am with you XenonMan. My hearing is not what it use to be back in the days of Rock and Roll at The Electric Factory here in Philadelphia. I recently purchased (1year) a chordette dac and use the bypass mode on my 990 and using my iPhone (bluetooth) I think my music sounds very good if not fantastic.
Granted put all of your sound meters, graphs and what have you the sonics reading b/c I am using bluetooth will not get as good a reading as from another from of playback but considering that I am streaming music I feel it sounds damn good.
I still at times use my Oppo 93 to listen to SACD's and also two channel.
Sometimes I have compared sound quality using my Oppo and streaming my iPhone using the same recording and I can be pretty critical but I did not notice that much difference.
Of course a younger pair of ears might notice even the slightest flaw in my music but I do not think to the point of dislike.