@midgardsormr.. Well if your players are able to avoid metagaming, okay. I have a couple of players who would completely change their tactics depending on how many damage dice I rolled.
I do agree that some open rolls add to the excitement of the game, however.
I actually use an electronic database rather than actual cards...but I still think cards are a good idea. I also have sketches of key NPCs which I display while the characters are interacting with them.