The employees here are knowledgeable and polite. The lines get super long in the mornings, around noon, and after people get off of work. Expect to wait 20+ minutes if you happen to come at these times.
I try to use the Automated Postal Center (APC) when I can and with that, I'm usually out within 5 minutes. I have never had a bad experience with it.
Also, when my sister had her three kids' passports done here, they were completely finished in less than two weeks! Woohoo!
This is #1 post office in Vegas!