I'm running a 28/29 warlock. No complaints. I can even solo multiple MOBs which I could not do without kiting in EQ.
I picked warlock over wizard because I think (means I don't know for sure) that more MOBs have heat/cold resists than disease/poison resists ... except for undead, of course.
BUT, you do have to know more about what your character can do in EQ2 to get the most out of it.
What's really interesting is that I can fight evens or lowers without having to use Heroic combos to win. Heroics are for yellows and oranges ...
Hope this helps ...