Wyred4Sound Remedy Reclocker does a good job on audio appliances like that.
Randy, that's a complicated question. Almost zero, but you are trading off bit-perfect for time-perfect, and that's anathema to some audiophiles.
A better question is, does it sound better with appliances like AppleTV? The answer is, yes it does, modestly. Is it worth the $300-$400 I think so, but not much more than that.
Alternatively get a DAC that is less source sensitive like the new Mytek's, Shiit's or Ayre Codex.