The employees at AI are nice as hell (I've bought a few guns there from Alphonzo) but the owner is far from nice. He's a retired SWAT officer I believe, and he also teaches their CPL class. In this class, he spends about 20 minutes slamming open carry saying how horrible it is, and has (from what I've heard) kicked out one or two people for defending it during one of his classes.
I've been going there for years, have probably been there about 60 times, and they've only told me to cover up the last 3 or 4 times, so I will not be going there anymore.
But there has always been a "No visible firearms inside the building" sign on the door, for as long as I can remember, which is all the way back since I was like 17 or 18 (so 2007, 2008ish).
Center Mass or Firearm Exchange are the definite places to go for me.