I never tried out Hunter (doesn't fit my playstyle) so I can't comment on its effectiveness in PvP or PvE. I started out with a Warlock and actually liked playing it until I made a Titan. After that my Warlock just sat there lonely and unplayed until I finally deleted him in favor of filling my character slots with Titans. I love using a Titan, I'll never stop using a Titan, and I really don't care what people think about me having 3 of them. It fits my playstyle, I don't get bored, and since I have 3 I can max my light level fairly quickly with a prayer or 2 to rngesus. All classes have their pros and cons and none are easier to master than another. If your playstyle is all offense, go with a hunter. Warlocks are an all around class. And Titans are your support/meat shield class that can still lay the hurt on.