I have a titan as well both subclasses are maxed striker is mostly a crucible build....go in and rock the ppl capturing your flag on control with FoH set the lightning grenade and watch injured foe walk back into trying to escape your gunfire but in pve it looses its appeal past tiger strikes....using FoH on the weekly nightfall or the raid will usually just get you killed on the other hand defender comes in very useful not only for you but the whole team i cant count how many times my life and the lives of my friends have been saved by that giant purple bubble plus with all the bonus shields like armor of light or the shield you can get from melee its the way to go and it also has viability in crucible to as ward of dawn plus armor of light is great everyone cant help but walk in the bubble to get you as if your taunting them and as soon as they do a quick shotgun blast or a few punches to the face means an easy kill