This past weekend in Tucson, AZ... I had a dealer pretty much openly mocking me for having a card. I asked him if it was a problem with house rules, he said "no." Then I told him that I would not slow the game down using it, because I had most of it committed to memory anyhow, but I wanted it there just in case, and that I kept it flipped face down when I wasn't using it.
The guy just would not let up. Every time I busted, he would say something stupid like "what does your card say about that?" So finally I said, "Did I or did I not just play that hand with perfect strategy?" To which he replied, "Yeah." To which I said "Well then there's your 51% edge. Now quit ripping on my experience level and deal me some winning cards. After all, if I don't win, you don't get tipped."
He finally shut up, but after a couple hands, we moved on. We just weren't comfrotable with him. We did complain to a manager, who did inform us it was the casino policy to allow strategy cards at the table.