This post might be of help to the less technically knowledgeable Outlaws. I purchased the 970 last summer to go with my 7100 amp and although movies have been great I was generally disappointed with the two channel stereo quality out of the 970 and wanted to find out where the weak link was. I am using the Yamaha DV-C6770 super audio / dvd-A player via the stereo line out for standard CDs. After reading an excellent review of the Squeezebox Silent PC Review - Squeezebox 3 I realized that you could actually get better quality sound by digitizing CDs than from a lower end CD player. Well, I just purchased a squeezebox and using the analog out on the squeezebox and the bypass mode on the 970 input, I now have what I would call good quality stereo sound and I haven't even converted to FLAC yet.
Perhaps the reports of better musicality of the 990 over the 970 comes from people in a situation similar to me with lower quality DACs on their CD players in combination with the lower quality DACs on the 970. In any case, with the higher quality DACs on the squeezebox in combination with my 970, I now have a digital cd collection and sound quality that is much improved and to my ears very good. Hope this helps others that might be in a similiar situation.