Just picked up our green cards from the attorney's office after they received them earlier today.
Here's a brief rundown of our case (I'm fuzzy on dates for the initial steps through I-140, but I'll do the best I can):
ROW, EB3 (myself + spouse as dependent)
EB3, filed for labor cert / PERM in late 2016 or early 2017, took much longer than anticipated 90 days.
I-140 filed with premium processing in mid-2017, approved within the promised period
Did the medical tests, etc. in October or November 2017.
Filed I-485 (w/ I-485J, and the I-131/I-765 for Advance Parole and EAD) in December 2017; receipt notice dated December 17, 2017.
Got biometrics appointment notice in a couple weeks for January 8, 2018.
Expected to get EAD/AP Combo card in 90 days, but it took longer; wife (dependent) got hers on March 20, 2018. I got mine on April 10, 2018. When my wife's combo card arrived first, we raised a service request to inquire about my status, and just got a cookie cutter response that background checks were still being done.
At some point during in March, we received a notice that our case has been transferred to Nebraska; we weren't sure what to make of it, but our attorney advised us that it was what it was, and not to stress over it.
Interview notice arrived in third week of April for May 17, 2018 (Houston, TX).
Went to the interview with our attorney, who prepped us well on what documents to bring and keep handy.
The interview started within 30 minutes of the scheduled time, and lasted about 45 minutes to an hour; the Q&A part itself was around 20 minutes - and we were asked to verify a bunch of questions on the I-485s for myself and wife: personal information, when we last arrived in the US, job, marriage date, children, whether I'm related to the employer (which I'm not), etc. She asked us for some documents to verify, and then asked us to sign the I-485s. Officer conferred with supervisor to make sure everything looked good, then told us we were approved and printed approval letters.
Attorney requested the office for an I-551 stamp on our passports (1 year green card endorsement), and the officer agreed. We left the office with the passports stamped.
We received the I-797 approval notices for I-485s and my I-485J on Wednesday (May 23, 2018). As an FYI, the online case status updates are hit or miss - as many have already noted. Even though we had the approval notices on hand, the I-485J still shows as being processed.
Per online updates, cards were mailed out on May 23, 2018, and today, on May 25, 2018, we have them in hand.
In hindsight, it was a straightforward process, but I wouldn't say it was without its stresses. We were advised at one time that we may be affected by overall processing delays (nothing related to our case, specifically), so we didn't think we'd be called for an interview or get the green cards before late summer / fall.
Grateful to God for helping us through this period and making things easy.
I hope this brief summary is helpful for others in the process, especially any wondering about experiences in TX / Houston.