The 5th generation Apple AirPort Extreme (AE) is an 802.11n dual-band 2.4Ghz/5Ghz wifi router that operates at a theoretical maximum throughput speed of 450Mbps, 150Mbps on 2.4Ghz and 300Mbps on 5Ghz using a wide 40Mhz frequency channel. For those on a budget, this router secondhand is an excellent choice. Its reliability is exceptional and performance good for a dual-band 802.11n wifi router. It doesn't support the latest 802.11ac standard, but for the majority of individuals it will do an excellent job for streaming multiple HD streams with practical real-life throughput exceeding hybrid fibre connection of 80Mbps and above when using the 5Ghz band and 45Mbps on 2.4Ghz band. It will outperform the majority of ISP provided routers for reliability reasons because it will establish a very stable wifi connection with wifi clients over the 5Ghz band that support this spectrum, which in the majority is a high percentage of wifi clients these days.
The 6th generation Apple AirPort Extreme is an 802.11ac dual-band 2.4Ghz/5Ghz wifi router that operates at a theoretical maximum throughput speed of 1.45Gbps, 150Mbps on 2.4Ghz and 1.3Gbps on 5Ghz using a very wide 80/160Mhz frequency band. For those that can afford the price of this wifi router, it's an excellent choice for future proofing wifi performance on a busy wifi network. It well exceeds the speed requirements of all planned upgrades for hybrid and pure fibre to the premises connections. It will handle multiple HD streaming and multiple protocol environments, such as streaming, copying files, VoIP, video conferencing, browsing, etc... concurrently with ease in most moderately sized premises with wifi clients that support the 802.11ac standard.
The 6th generation AE also handles switching wifi channels automatically on the 5Ghz band more intelligently than the 5th generation AirPort Extreme, which will only use channels above 100 and manual selected channels from 36 to 48 and will detect none complaint higher frequency DFS wifi clients and switch the wifi channel accordingly to the lower frequency bands, of which there are two lower frequency spectrums on 5Ghz. It is also completely ready for the IPv6 Internet protocol when it arrives soon, generally. Latency is half that of 802.11n 5Ghz on 802.11ac and considerably more stable because of beamforming antennas transmitter/receiver technology, which is great for those using wifi game consoles, but generally, you should hardwire these consoles for best latency. But you could get away with a game console that supported the 802.11ac wifi standard, of which there are none to my knowledge currently that support 802.11ac for lower latency because it's about 7ms on average without excessive jitter on this wifi standard during my real life tests.
When setting SSID names most state you use the same SSID across all access points and frequency spectrums, my advice is to use the same SSID across all access points of the same spectrum only. My main reason for recommending this method of setting the SSID differently across 2.4Ghz and 5Ghz spectrums is better performance and less interference from 2.4 GHz sources, that have a drastic effect on VoIP, video calling/conferencing and IP TV streams that cannot tolerate interference of almost any description for it causes high latency jitter. If one experiences range difficulties on the 5Ghz spectrum then use more wifi access points around the premises and connect these by either Ethernet cables or Ethernet home plugs for the 5Ghz spectrum. Don't allow dual spectrum wifi clients to pick the 2.4Ghz spectrum in preference to the 5Ghz spectrum ever these days, even Apple wifi clients get it wrong often and this will be a headache when using the above services because they will be drastically impacted when using the crowded and longer range 2.4Ghz spectrum that your neighbours will be using unless you live far away from everybody.
AirPort Extreme 5th/6th generation dual band wifi routers
Moderator: embleton