2013 32GB Nexus Wifi only. Eastern US location. Missed out on the initial 5.0 OTA (ignored the announcement message, then it vanished). Just tried "check for system updates" and saw 5.0.2 was available. Downloaded quickly enough, feels like 15-30 minutes to do the reboot, install, and optimizing steps (sorry, forgot to time it). So far, everything appears to be there and working.
I am getting a persistent (haven't waited more than a few minutes or rebooted yet) warning about an app needing permission to update, it opens Google Play Services, but only shows options to deactivate or open. I did go through and check on various settings for apps, location services, etc. Looking at the app reviews, other folks are seeing the persistent warning message.