Wow, I checked out those metal business cards, they are way too cool. But I bet they are extremely expensive. I do not think it would be necessary specially if you attend one of those conferences or business trades where your business cards are treated like flyers. One moment you are giving your business cards like they are precious gems, then the next,you would see your card lying on the floor.
I used to work with this marketing guy who won't go out and get clients for us unless he holds a printed business card with his name on it and he would not settle for calling cards that are printed from our office computer printer.

Lol. Well, I agree with him, quality business cards can signify professionalism.
Business cards are good marketing tools but only if you hand them to the right people.
