Sketchy AirPort performance has been bugging me for weeks, probably over a month now, and I've been going through all forms of troubleshooting with my AirPort Express trying to squash the issue, but to no avail. My MacBook and iMac drop their Wi-Fi connection seemingly at random, sometimes right in the middle of Unreal online, and never regain it unless I manually re-select the network. I've been following the typical methods of changing channels on the APE, reducing range and using Interference Robustness - but it's all been for naught.
Now, Apple has released a support document that might provide a solution for those like me who are experiencing less-than-stellar AirPort reliability and connectivity with their Intel Macs. The document specifies that these issues are related to the use of WPA2 and upgrading to 10.4.8, and I can't offer any feedback just yet as to whether my problem has been solved, but this doc is at least a step in a troubleshooting direction other than 'pull out more hair.' Feel free to share your experiences and any solutions in the comments.