I wouldn't touch Warlocks with a 10 foot poll right now, and I have to play one. My guess is that at least 2 out of 3 of my guild's Warlocks, and more likely all 3 (some encounters) are going to be benched during Mythic progression.
I have absolutely despised playing my Warlock since the 6.0 patch in Siege of Orgrimmar. I was previously a melee DPS main, but swapped due to necessity for the guild. There is very little you can do while moving now, and it is a painfully boring class (at least for me) to play.
Everyone loves Mages and Hunters right now, roll one of those.