Mac vs Squeezebox

I'm currently using the following setup for digital music: Macbook and iTunes (with external HD) streaming music to a second MacBook, which then goes into a DAC and my system. My question is: In terms of sound quality, would there be any benefit in getting a Squeezebox? Assuming that the Mac settings are optimal, can I conclude that the bits are arriving at iTunes intact, and that it's about the DAC and everthing after that?