Ok, I know that the "figures" for wireless networks aren't exactly correct. After you subtract out overhead, you can expect to get around 5Mbps for 802.11b and 25Mbps for 802.11g. I did some testing and found these results:
With an 802.11b device plugged into my network:
Power Mac G5 (802.11g) ftp to Powerbook (802.11g): 650KBps (of roughly 5.3Mbps).
With only 802.11g devices on my network:
Power Mac G5 (802.11g) ftp to Powerbook (802.11g): 1.3MBps (of roughly 10Mbps).
So something isn't right. Things look good on the network when the b device is present, but when I am all g, I should be getting much better speeds. Both my machines are very near the base station (both have full signals). Any thoughts on what could be slowing down my network? Is the Apple Airport Extreme a poor choice in wireless routers? It has been very reliable (my old Linksys would lose wireless signal every other day, requiring a reboot). I would have no issue upgrading the device (to either Super G or 802.11N), if I would see any kind of a speed increase on my G devices over the existing speeds I am getting.