Passport Stamping experience in Denver Colorado

I travelled from Colorado Springs and it takes about an hour and 15 minutes to reach the Denver USCIS. I reached the USCIS office at 5:50am
There were about 10 people in front of me. By 6:45am the Queue had grown quite a bit, So I would suggest anyone going to Denver to be there not later than 6:00 am. At around 7:20am they opened the main door and asked each person in the line what they had come in for. I said my I-485 has been approved and I have come for Passport stamping. They did not give me any token number (although a friend of mine who went for the same thing - Passport stamping was given a token number). Anyways I was asked to stand in the first line for Window number 7. You have to go through a Security Clearence, which my wife and I did. I was third in the line. The window opened at about 7:45 am. The lady at the window asked me what we were there for and I told her that we were there for getting our Passports stamped. She took our passports, Two photographs each, Our copy of the I-485 and the EAD Card for my Wife (I did not apply for an EAD card). After that she put a cross mark i.e Cancelled out our Visa page in the passport. After that she directed us to the last window where they took a Signature and fingerprint (twice) on a form. After that we headed back out. It took us not more than 10 to 15 minutes for the whole thing and we were out by 8:00 am. But think about it if you are about a half hour late and the line is pretty big then the wait could be much longer. Say there are 10 people before you in the line to get the Passport stamped then you have at an average 100 minutes to wait (or atleast an hour). I have had friends who have waited for 3 to 4 hours for this just cause they were a little late (They reached at around 6:45 or 7:00 am).