USCISC online says 4/24/2018 greencard was ordered. Same note as the physical "approval notice"
Case was transferred to NSC, the Approval Notice was sent by NSC. I got both letters at the same time, because I check my mail once or twice a week.
NO1 12/21/2016
notification for bio 1/7/2017
bio 1/27/2017
For those of you feverishly checking your physical mail box for notices, I used the USPS "Informed Delivery" service. Its free, you sign up online. They email you images your physical mail envelopes for current day's delivery. This is how we know that we had letters waiting in the mail from USCIS.
I received two letters:
Notice Date 04/19/2018, Transfer Notice, my case was transfered to NSC
Notice Date 04/24/2018, Approval Notice, saying my case was approved, expect greencard in 60days.