If you are a casual gamer, I think you will find this game very enjoyable. It is fun, and DLC adds some more entertaining elements to it. Might as well get the game while the DLC is free!
casual, i think Brink is more for the hardcoe gamers. You actually have to work together, move in synch with your team. Buff each other, communicate, you can't go all lone wolves like you can in Halo.