Performance of Apple AirPort Extreme base station wireless access point
The AirPort Extreme uses the 801.11g draft-compliant standard, which is still under development and by no means complete. The unfinished state of the standard means a couple of things: One, you can expect frequent firmware upgrades as the standard itself changes and moves toward completion. Two, you'll get faster performance if you're using the AirPort Extreme with other 802.11g devices.
In our tests, the AirPort Extreme achieved impressive speeds when set to g mode. It delivered 16.8Mbps of throughput at distances up to 25 feet, compared to 14.5Mbps for the Linksys WRT54G Wireless-G broadband router. However, performance dropped off quickly as the range increased; we couldn't even get a consistent signal at 100 feet, even though Apple claims that the base station's range is 150 feet.
Like most wireless-g devices we've tested, the AirPort Extreme's performance also plummeted once we introduced an 802.11b client and moved into mixed mode. Speeds in our tests hovered around 5.7Mbps--typical for an 802.11b network--and dropped like a stone when we moved more than 50 feet from the base station. In short, invest in the AirPort Extreme only if you plan to create a whole new wireless-g network; it's not worth upgrading if you're happy with your 802.11b AirPort base station.