My router, 1st generation AirPort Extreme, is 802.11n 2.4GHz and 5.0GHz capable. Whenever I turn it on, instead of 802.11b/g/n the network slows down considerably within a few days. This probably is because of bad firmware => the router running out of memory.
Do the newer generation AirPorts have the same issue with 802.11n? The 1st generation is quite old and I was surprised it actually supported 802.11n.