Just did some quick online research on the Wadia S7i as a transport. Found a professional review by Christiaan Punter from April 2012 stating in relevant part as follows (my emphasis):
"The Wadia S7i's transport has been optimized for accurate playback and it shows. Using the S7i as a transport only into various DACs, it performs in a consistently tight, fast, dynamic and lively manner. Comparing to the Marantz CD11LE or Levinson 390S as transports, the latter two have more color and a smoother, more relaxed presentation that I favour. But in terms of quality this is a matter of taste. The S7i functions well as a transport and as a DAC, but still, I prefer that S7i playing CD's in an integral manner. This way it just sounds most involving."
Perhaps the Wadia 7Si spinning a CD and outputting via Toslink is not the ideal transport/source material to show what the Ayre QX-5 can do.... Just sayin'.