A quick word of caution. Although I’m a fan of eero (starting before Amazon bought them), if you’re a HomeKit user, there is an obvious oversight in their software of which you should be aware.
Replacing an old eero device with a new one is easy using the eero app. But, when you delete the old device, the unit is not removed from HomeKit. And once the device is removed from your network, you can’t delete it from your home. You’ll be forever stuck with error messages about “non-responsive” devices in your Home app.
eero tech support confirms that there is no way to fix this after the units are decommissioned. Clearly, their software should either do this for you automatically, or alert you before you shoot yourself in the foot. But it does neither. Fair warning.