USAnewcomer

the little brochure with the green card? That's your "welcome letter".

Is this brochure the one? It has 124 pages.

http://www.uscis.gov/sites/default/files/files/nativedocuments/M-618.pdf

Here is an idea as I see it:
As a citizen you are entitled to get into country. As a foreigner you don't have such rights.
Therefore, it's better to enter the US with an US passport (or a green card). There are officials on the border who make decisions. The same goes with other countries.
It doesn't matter IMHO what passport you show to the security. They just check your luggage.
It doesn't matter IMHO what passport you show during the check in. They are just air company's employees. I would show them 2 passports.

I agree that it's different in China. But people still manage to do it somehow.

Green card delivered today (POE May 10th, ELIS fee paid in December).

I have not got a welcome letter. Do I have to call the USCIS phone or send an email?

Btw, I knew my address on file was right when I got a reply from them by a regular mail to my previous email.

My status has changed:

"On August 4, 2014, we mailed the new card directly to the address we have on file."

No tracking number is provided yet.

My status changed to Card production. Elis is still optimized. What is the next step?

Same here! I just checked my satus.

Hi guys,

I need your advice. I'm stuck at the "optmized" stage at ELIS.

Before I was stuck at the "submitted" stage. After 45 days I sent an email message through ELIS. USCIS people created a case at the Texas center. Then I was moved to "optimized" stage and was said by the Texas center to wait up to 90 days. Now 30 days have passed.

What can be done now besides just waiting? How can I contact the Texas center by email?

Thanks in advance.