My Airport Express works great. Audio quality is amazing.
Disappointed it broke VolumeLogic from www.octiv.com
and all products from www.rogueaomeba.com,
such as Detour and AudioHijack. These work when computer speaker/headphone jack is selected in iTunes, but not when Airport Express is selected.
So there's only two ways to control volume - the iTunes slider and the stereo itself.
Hopefully these will be worked out over time - in addition to piping audio from other apps to Airport Express.
PBG4667 Titanium, original internal Airport card 80211b acting as base station, AE in client mode, works simultaneously with Ricochet wireless ISP (PC card modem).