I love the Cowboy Junkies and I found that their recordings are above average. But onto your question.
My system still floors me when I take the time and sit down and really listen like you have. For me though, its all dealing with vinyl because I'm rediscovering my old vinyl because of the new turntable I purchased last year. I've heard nuances with my vinyl that I didn't recall hearing from the previous turntable.
As far as CDs go, its the latest CDs I've purchased where I haven't had the time to sit and listen also surprises me.
Its the subtle nuances from either medium that effect me the most and I think its these nuances that makes listening to music as whole, a rewarding passtime. Good post itschris