I have never seen this played in a competitive tournament but I have faced it a couple of times in casual play. It is a nice common card that unfortunately doesn't see a lot of play because so many other cards seem to bump it out of decks during construction. The biggest benefit for this card is that it lasts the entire turn so once played it will reduce all the attacks form that source. So played against a Feral Thangral, or a Windseer Tarus, or a Galeway Steamwhistle buffed Warrax the effect will carry over to the second (and in some cases third and fourth) attacks as well.
I can't see this card getting a lot of play because it just doesn't give you a lot of bang for your buck.
This post was posted both as a review on tNook and as a Church of the Game post.