Played the story mode with my friends and it seems their thought process was to make incredibly short maps but to make it a challenge they keep the enemies re spawning at a high rate with ever stronger guns. The control interface is clunky, your guns have little to no effect on the enemy in co-op. It is incredibly hard to finish off a opponent on co-op emptying two magazines into one who is already down is absurd. Figuring out when or why a character has not gone down is difficult, hit tracking is weak also.
Brink does look good beyond that I do not have anything positive to say. I was hoping for something almost as good as Borderlands but I am sorely disappointed.
Bottom line: save your money