Did you happen to write up the results of your router tests? I'd be really interested in reading up on them! I recently picked up an old Apple Airport Extreme so I could easily set up Time Machine backups on my network, but obviously Airports have their own host of issues so I'd be really interested in upgrading soon.
I don't, but it was a narrow case. Part of my home-made home automation runs on wifi so I was focusing on low latency and no packets lost when using wifi in my specific building. Top of the shelf routers all had some occasional hiccups. I think the good old WRT54GL did much better than them. Plus it was done with the set of wifi receivers available to me at the time (mostly cheapos connected to rpis & esp8266).
This is not a common use case, I was not interested in high bandwidth. I did try to disable beamforming and all other fireworks when testing though (but did tests with default settings too)
A second-hand Mac mini is an alternative that I've used for network Time Machine backup targets. Can also turn on caching iCloud/App Store/system updates for your home, if bandwidth is metered and/or slower than your local speeds.
