The new Synology router looked very interesting, but I opted for the google wifi 3-node mesh router. To cover the entire house and back patio, i would at least need two routers, so the three node mesh solution seemed perfect.
Good or bad the google wifi has even less options than the Airport Extreme but did have a few diagnostic tools (speedtest, mesh test, location test) that Apple didn't have and also told you who was consuming the most bandwidth. One feature for parents is the device pause feature where you can set some boundaries with those that annoy you.
It did take several days for the everything to settle down, the access points/mesh nodes didn't initially take to the ethernet backhaul, and i was very tempted to just return it, but now it's working very well. There's no snmp features, which was something that you were after.
Jim