"Did you expect the C15 to sound as good as 808.3 which is double the price?"
Well, why not? The 808.3 is in fact a CD player,
While I am more pissed than most with M's customer relations I take some exception to your post.
You answered your own question. The 808.3 is a CD player. To get CD quality from a music server you need an MS600 as I have elaborated on too many other times to repeat again. With that a MC200 is as good as an 808.3 spinning discs, if not better.
I think M's MC200, MS600, ID40, AC200, DSP3200 and 861v6 are pretty darn terrific additions to the lineup, with of course the 8K past present and future being the creme de la creme.
I would love to give M headquarters a shake about their curtomer relations, but fair is fair on their products.
Aloha,