I've seen an increase in Warlocks on AP.. but that really shouldn't matter. Play what you wish.
Both classes are super squishy, until well geared. (BoA's, LFH, etc.) & even then, you can have hard time to thrive without competent healers on your team. DPS is relatively low, compared to other classes/spells in this bracket, but where we lose out on damage, we make up with great support for the team. In the end, you just need to accept the fact that you're going to be unbalanced against the rest of the bracket, but imo, that can make for another interesting challenge. When all else fails, for example, my objective becomes the survival game.