If you've just recently purchased an Apple AirPort Extreme or Time Capsule, you're in luck. AnandTech has published a detailed review of the new devices showing that they have faster Wi-Fi capabilities than their predecessors.
The new devices are physically identical to the earlier versions, with the model numbers -- MD031LL/A for the 5th generation AirPort Extreme and MD032LL/A for the 4th generation Time Capsule (2 TB) -- being the only giveaway. As with previous models, the devices come with four gigabit Ethernet ports and one USB 2.0 port.
AnandTech found FCC documents showing the power output for the new and old devices, and in almost every case (with the exception of 802.11b on the 2.4 GHz frequency) power output has essentially doubled (see image above).
The tests performed by blogger Brian Klug show that the new devices provide faster throughput, with upstream file transfer speeds being more than doubled when used with a Mac with a current generation internal Wi-Fi card. Downstream throughput, measured with the Iperf network testing tool, was also impressively higher.
The TUAW blogging team often debates whether it is worthwhile to regularly upgrade network infrastructure, but the test results seem to show that in the case of the new AirPort Extreme and Time Capsule, the upgrade is definitely worth looking into.