I have to say the main things I noticed are treble purity, big increase, no grunge. The attack, notes have better 'pop' into existence with the Sa-10.Mainly I play CDs. All the time. (I own 2500 Cds. and maybe a dozen SACD.CD dual discs. Plus I do not actually use the SA-10 transport! I am 'saving' it and I use the SA-10 as a DAC for usually a five disc CD changer via Toslink to the SA-10.(Though I also have a Technics DVD-A10 I use via SPDIF RCA, sometimes)Anyway the main thing is how different CDs can vary in quality. Something much more apparent than before. The worst 'bad' meaning I can tell they used 14 bit encoding or something, cheap microphones??.. And that there are 'superdisks' just like there are in LPs. Some are just amazing recordings. Detail, depth, amazing performance..Can hear each breath, every detail.. Others fuzzy, muffled. So the medium is much more a part of the process than ever before.