My understanding of your question is that you wonder if MC give the same dynamic range as your cd player. From my experience (based on my ears), it does. There is no difference in dynamics compared to my old (and quite good) cd player. As a matter of fact, MC sounds much better, but that is becuase I now have a far better DAC connected to my pc than the ones used before in my cd players. And bit perfect harddisk flac rips of my old cds to avoid real time correction algorithms in the cd player. I have of course no volume normalization in the signal chain.
I can not understand why iTunes should sound dynamically compressed either, except if you 1) have heavily lossy compressed music files or 2) use volume normalization or 3) use a crappy DAC and hook up e.g. a laptop using minijack analog out (have you heard the amount of electric noise you can pick up?).