Visa Stamping from Canada/ Mexico

This forum has been a lot of help and am hoping this will be helpful to others.

I and my family (wife+daughter) had our interview on 7th July at 12:45.

We were sent in at 12:45, and the first step was a document check of the Passports and DS160.
Then went through the security (no mobiles allowed). And down a flight a stairs and took the elevator to the 19th floor.

Once in the 19th floor, a lady cross verified the DS 160, put them in a laminated sheet and asked us to get in the Q for formal document check.

We went through a Document check where the details of the documents were verified against those in the system. I was asked to pay a Visa fee at a separate counter (this is based on the type of Visa and not everyone had to pay this).
Once the payment was done and I submitted the receipt at the first counter, the document check was completed, the documents and passports were placed in a particular order in a cover, and we had to go to the next counter for fingerprints.

Once done with the fingerprints, we were sent in for the interview.

A wait of about a minute and then the Interview.

The Visa Officer was very friendly and made us feel comfortable.
She took the documents with passports and asked for my my Canadian work permit, marriage certificate and birth certificate.
She asked some questions about my education, job, organization etc and was cross verifying the documents and answers against what she had on the computer.
After 4-5 minutes, she wrote down the visa validity dates, Visa type on the I129 document,
One set was returned to us and the officer asked us to carry the documents along with us when we enter the US since the Customs and Immigration officer might ask for this document.
She wrote down the same details on the other I129 and kept that with herself

And then "Thank you, You will get your passports in 1 week."

So out of the 3 sets of documents, they will use 2 sets, keep one for visa processing, return one to you.
The 3rd set is an additional copy.