I loved these routers. They always worked great except up until late. We ended up having issues with them overheating and turning themselves off
This really shouldn't be happening, do you have it close to Windows under sunlight the router has been bought for many years ( more than 4 - 5 ) where thermals paste are acting up.
The reason I said this is because Apple actually down clocked the internal Controller within Airport to ensure its stability. This also means it runs cooler than most Router. ( And also a reason why its WAN and LAN speed aren't top notch )
There were many possibilities for better use of airport and iOS integration, such as caching OSX / iOS downloads for installation to other devices, backing up your iToys locally... etc.
That is actually a features available on macOS Server, something I really wish Time Capsule has it as well.