I'm not thrilled about the autoupdate feature of Google WiFi. I wouldn't be surprised if it's leveraged to benefit Google's analytics, or for government snooping. But the greater risk at this point is from criminal hackers. And I prefer running my WiFi routers in bridging mode, anyhow, making it less likely Google will bother tracking my family's browsing from the LAN.
Maintaining my own homegrown router isn't appealing, though. For one thing, all the hardware available for that is sub-par. Solid support for MIMO and beamforming is mostly non-existent except for proprietary stacks; even simultaneous multi-channel is iffy using open source solutions. AirPort always shipped with better than average support for the latest tech, and I'm not keen on going backward in that regard, especially for what should be a performance upgrade.