DACs: Airport Express vs waveterminal vs mini-dac

I was interested enough in this whole topic to buy an Airport Express and check into it for myself. I followed some of the info on Audioengr's website and used the Exact Audio Copy software for ripping CD's uncompressed to my PC HD (Compaq tower, fairly new). I bought a compatible USB wireless device and also the little Apple remote that plugs into the AE USB port.
I use the Monster mini to Toslink cable and run that into my Audio Alchemy DTi Pro32, where I messed briefly with increasing the word length from 16, 18, 20, 22 up to 24 bit. The DTi then goes into an MF A3 24 Dac which upsamples to 192khz.
We had a club meeting on Sunday at my place, so we spent a little time comparing the PC playback with playback through my transport.
The main drawback with the PC front end is on busier passages where the music seems to collapse a little (compress). In most cases it comes fairly close to the sound quality attained via the transport, but has never sounded better, only similar or slightly inferior.

I wonder if there are improvements to be had at the copy stage, perhaps some of the many parameters in the EAC software need to be set differently?

Has anyone using a good transport had better results with the AE and a Mac or PC server?

I'd be interested to hear if it's possible to improve the performance using the hardware that I have.

Cheers

Well the whole project has, thus far, come off without a hitch. They system sounds excellent and I love having music at the scroll of a mouse. Now for the long, arduous task of importing all my music to iTunes....

Followup:

I was in on this thread earlier on and wanted to let everybody know where I am now. I did buy a U24 to use with my G4 iBook. I purchased the Apogee Mini DAC and have my Sennheiser HD650s connected to the Apogee via XLR outputs through a balanced Zu Mobius cable. I listen almost exclusively to classical music and am a professional musician. This setup is astounding. I can't stop listening.

I am using the U24 as well, with nice results. But I want more. I am trying to decide between the Apogee USB Mini DAC and the Benchmark DAC 1. Any opinions or experience?

I just figured out that I can get lots of great radio through my computer/internet as well. I can now sell my changer and tuner if I want. I am thinking about putting my money towards a really good DAC since my computer is turning out to be the heart of my system. Now that I have ripped my 500 cd's to computer, and have all the album artwork loaded as well, I can't believe I didn't do this sooner. I am rediscovering my music collection and listening to stuff I haven't listened to for years. It would not surpise me if we begin to see a lot of USB DAC's on the market very soon.