I just played my first crucible game as a titan defender. I won, brought my team back from a 7000 point blow out. We won by like 600. My k/d was only 1.11, because I killed myself like 3 times by flying off an edge... But other than that, I would say that the titan is a little crucible weak. I had to rely on a good trigger finger and luck to come out of that on top, not my super ability like many others.