There are songs that I hear on XM that just don't have the sound/impact of the songs I remember. Example: "The Ocean" Led Zep, album "Houses Of The Holy". The drum lick that John puts in that song, made that song!! It was the highlight of it. Today when I hear it on XM or even the local radio station, that triplet kick is almost unheard now. So younger people that hear it today for the first time will not get the very important 'feel' of the song.
Seems that radio today has computerized all music to eliminate the "loudness difference" with algorithms that have effectively drained the dynamics and altering the mixes of once great recordings!!
ZZ Top "LaGrange" is another example, when it was released on CD it had way too much reverb on it. Did not have the same sound as the original. Kansas "Leftoverture" release on CD was the same way. Way too much reverb. ZZ Top corrected this when they released their "Studio Albums" box set. Thanks Billy! (However, some radio stations still use that over-reverbed versions)
I could go on... but I will stop this rant from getting out of hand!!
Blame it on @craigb, he got me started!!!