ATT US, yes. Have not left the GMT+5 time zone since having the 920 though so don't know if there would be issues if travelling. Been flawless even with a couple freeze and reboots. No factory resets.
Sort of, the time isn't right as it is always 1 minute out (exactly 1 minute), but it isn't drifting so I assume it must be getting it from somewhere as my Lumia 710 would drift by several minutes a month in auto.
Edit: forgot to say Orange UK (EE) using a unbranded UK 920
Hello guys..iam using a Telstra Australian model..it works perfectly on their sim but not if I am using Vodafone sim.. Ian currently in the Philippines for holiday..globe doesn't do auto time as well..very annoying.. My old iPhone 4 works flawlessly in auto time irregardless of which sim I use.