Coming from the Netgear Orbi due to the reboot issues that many may have read about, I am also particularly interested in knowing the UP time as well. I'm sure there are quite a few "converts" from Orbi to Eero because of the rebooting issues plaguing the Orbi.  I have a home automation system that tracks internal IP addresses on the network using FING. Through this I can see that since the 28th of December I've lost access to the Eero router nine times. One of which was when I ran the firmware update which was expected. The other times were mostly at the beginning: 5 times on December 31st and once on Jan 1st, twice on the 2nd. I do not think it is suffering from the same issue that the Orbi was with my Android devices since that would reboot the Orbi many times a day. 

I have almost no doubt that the loss of the ping from the fing program was a fing (and more to the point...ping) related issue. I say ALMOST because I am still very gun shy having wasted $400 on the orbi system which is sitting unconnected on my work bench and having paid $350 a week and a half ago for the Eero. I'll give the uptimerobot.com system a try hoping to either confirm or deny any results I get from my internal fing scans that are always running here. Any thoughts on other options I can use to check that may be more reliable than Fing?