As of this version (1.1b1), Airport Monitor Utility does not support auto-discovery of the Airport Express. I ran the utility but my AX was not discovered. When I selected the Drop-down menu for basestation type, the only two options were "Snow" and "Extreme". I had to manually enter the AX IP address which is inconvenient since I have DHCP enabled and I had to check the DHCP table on the router through which my AX is connected to the internet. Once I input the IP address, it found the AX and I was able to collect all the information.