Squeezebox vs. Apple Airport S/PDIF comparison?

[Deadreckon]

Has anybody compared the Squeezebox 3 to the Apple Airport Express S/PDIF optical out? I believe they are both bit perfect, so is there any quality difference (e.g., jitter)?

I currently have the Airport feeding my DAC, and prefer using the iTunes program. Has anybody evaluated the Airport's jitter? Can I do any better?

[Deadreckon]

I found this from a Stereophile review, so I guess the Airport optical out isn't too shabby:

However, this performance becomes moot when the AE's digital output is used. The grayed-out trace in fig.7 shows a similar spectral analysis of the Musical Fidelity X-DACV3's analog output while it was driven by the AirPort Express via the Monster TosLink cable. The noise floor has dropped by 4–5dB, the word-clock jitter to a respectably low 258ps, which is actually better than the case with the standalone D/A processor driven directly by my PC's S/PDIF output (provided by an RME PCI card).

http://stereophile.com/digitalprocessors/505apple/