I have a Hunter and a Warlock.
I much prefer playing with my Hunter than my Warlock. The play styles differ, at least for me. I take far more risks with my Hunter than with my Warlock due to the quickness and escapability. On the other hand my Warlock has resurrection, which is also very helpful. Yet Warlocks tend to be more squishy and slow.
I believe all classes are pretty well balanced. Titans and Warlocks are more team supportive, with Titan bubble buffs and Warlocks clutch resurrection. Hunters don't really have a team support roll so it lets me focus on purely murdering NPC scum. Which I much rather prefer.