Here's the drill: (1) Walk in. (2) Make sure someone signs you in. (3) Patiently wait for your name to be called. (4) Get whatever service you need.
Here are some things you need to understand: (1) The world doesn't revolve around you. You need to get in line like everyone else. (2) When the new iPhone launches, there will be massive crowds. Visit at your own risk. (3) Workers are people too. When you show up near closing time, they're bound to get irate. While there is no excuse for this, it doesn't help to add to the anger. (4) If you visit near closing time and the workers ask you to come back another time because they can't possibly help you in a timely manner, you may want to take their advice. Besides, they're only telling you for your own good. (5) When all else fails, please see #1.
I visited to have my phone activated. I followed the drill. Luckily, the wait wasn't terribly long. When I was finally called, the woman who helped was kind and patient and addressed all my questions. No fuss. No muss.
When I was there, there seemed to be a lot of associates around helping out. No one pushed any products on me and everything ran smoothly.
If you want a pleasant experience, you gotta know the drill and understand a few things...