Alpha3,
What's now gone is something I thought wouldn't exist (much) in a $1K cdp; I'll call it digital harshness. The tweeters in my VSA VR-4SRs are very hot, so any crap in the high frequencies are in your face. The most obvious change when going to the DAC was the clarity and smoothness (if those terms aren't mutually exclusive) of the upper frequencies. I heard triangles in songs I used to think was the drummer hitting the bell of a cymbal. Vocals are more realistic, do I dare say sweeter? Bottom end has more authority and again, clarity. I suppose all of the above also helps provide a better defined soundstage which I'm also now getting.
Some CDs I have were too irritating to play before. I can listen to those again. And the ones that already sound good, well I just enjoy the music more and the "sound" less.