Airport Express compared to High End Transport.

I would love to hear from people who have compared the results of:

(1) Streaming music from a computer via Airport Express to a high end DAC via the optical output on an Airport Express.

(2) High end transport connected to the same DAC.

What were the sonic differences between the two? I suspect the high end transport was better, but thats just a supposition.

Many thanks in advance for your thoughts on this.

All the best,
Neville