In PvP, the main issue I have with Sunsinger and Stormcaller is that when activated a lot of people (including me) get the feeling of being invincible, charging head-on at enemies which can result in you dying before you have finished the super. With the Nova Bomb if you do manage to get killed whilst using it, it normally cancels out the attack and you can use it again after respawn. I'm also a big fan of Axion Bolts and The RAM, though I will mix up my build based on game mode (for example, when I want to control the path through a level I use vortex grenades). In PvE I like to also use Voidwalker, the main reason being that I find that my fellow Warlocks rely too heavily on self res and so take risks, whereas as I know I don't have that crutch I'm a lot more cautious and methodical. Also because I'm the relic runner and I like to slap the Vessel with a Nova Bomb after I've stolen the bubble off him :) Either way, whenever I see a Warlock on patrol I always give them a wave, no-matter what their subclass :)