I haven't played crucible with my warlock but I find the titan is better overall than my hunter. Obviously invisibility is good but it's not true invisibility and the Arc Blade is relatively easy to counter if you time it right. GG is good but hunters overall are pretty squishy so can't take much damage compared to titans. Plus I've found if you get killed on activating Fist of Panic (but before you kill anyone) you don't lose the super energy yet if you get killed in the activation pose for Arc Blade or Golden Gun you do lose the super.