Mention status when asking for upgrade?

Hi all, bit of a newbie question. I'll be visiting the Doubletree Alexandra in Barcelona in a few weeks and I'm HHonors Gold for the first time. When checking in, do I mention my status when I ask for a room upgrade? Do I slide my "gold" card across the desk? (I have no idea what this card is supposed to be used for anyway.) And does the answer to this question depend on the brand (i.e. Doubletree vs Hilton vs Conrad.)

Thanks in advance. Love the forum!