Plus, as Mr. Schroeder states, whether you can actually surpass the sound quality of a high quality CDP is debatable.Everything in this hobby is debateable, and is.
The goal may not be to "surpass the sound quality", as you say, but rather for convenience. Can it be done with no loss of performnce? In my opinion I see no reason why not; and my limited experience bears this out.
Like you, I found the thought of creating a hard drive based system a bit daunting, though I believe this is (and will be) improving. This is why I found the Wadia i170 so intriguing when I first learned of it, as it was a way for me to do such a thing that seemed easy enough to me, and was. (That said, it lacks some great features of a PC based setup.)
I see no reason one has to rule out either option, although the future seems to be hard drive based.
Brian