Apple rarely disappoints and always works as advertised and the Airport Extreme is no different. I bought 3 Geek Squad Refurbished units and the only criticism I can give is that unlike Apple's Refurbished units, the Geek Squad units were all scratched, some were smudged, and all were covered in gobs of adhesive from what I assume had been large stickers on the sides of the units. That's the bad.
The Good is that those issues are all cosmetic. They actually work just fine.
I'll forgo the usual boring review & reveal a trick/ hidden menu & features I found along my recommendations for who should buy this router & who should not. Bsdically, it's the ideal router to buy for your college student (I'll explain why) among other types of consumers & home networking situations. But first, the hidden menu.
In the Apple Airport Utility screen, you can hold down the 'alt' key while you click "Edit" in the Utility window to get detailed information about each of the devices connected to the network. You will see a list of your wireless clients (connected devices) either by their customized names (if you've done so), product name, or their individual IP address. Each device has a triangle icon that is a drop-down menu which when clicked, gives information on IP address, MAC address, quality of connection, data rare (connection speed), RSSI, and the PHY Mode (802.11ac or n or b or g, etc.). It is very handy.
Most users don't know this hidden menu exists or that the Airport Extreme can even give you this information.
I also can attest to IPV6 working beautifully on my network. Your ISP & cable modem both must support & connect to IPV6 in order to justify enabling it on the Apple Extreme, but mine did (I used a common IPV6 test site that you can find online) and my Apple Extreme has been seamlessly connecting to IPV6 sites ever since.
I live in a congested area of condo living where we not only have numerous overlapping networks but also a glut of Comcast Xfinity gateways hosting xfinitywifi hotspots for general use. The Apple Extreme operating on the 5GHz weather bands has been an advantage I won't soon give up.
The Extreme is actually an AC1750 router (most people don't know that) and despite lacking QoS, beamforming antennae, MU-MIMO, mesh, and some other of the newer features routers now flaunt, it holds its own against higher ac routers double or triple that - even the new Velop. In tests for throughput in small to mid-sized homes the Apple Extreme only starts to lag behind where these routers like Google wifi, Linksys Velop, etc., are engaging mesh & MU-MIMO to cover large areas and hard-to-reach corners. If you don't live in a McMansion & want excellent 4K streaming speeds, the Apple Extreme is an excellent choice. If you are a gamer in a 5,000-15,000 sqft home with 20 wireless clients, then you should be buying the Nighthawk X10 or the Asus.
Despite Apple seemingly turning their attention away from home networking, the Apple Airport Extreme is still an absolutely solid router - no fuss, no muss - for those people who aren't looking to flash DDWRT or customize their router in the same way phones & srreaming boxes are jailbroken and for anyone who wants to buy a solid router they know will work out of the box with few if any limitations and little to no intervention or networking knowledge needed. It's also the IDEAL router for your college student who needs solid performance, plug & play setup, excellent manufacturer support, and can work well in extremely congested high traffic areas like apartments, dorms, & campus living.