I was average at best in pvp and never played a mage. Also it is rock, paper, scissors (RPS). But if you put these two up 1v1, Lock should win. It was my easiest kill easily where as the rogue beat me nearly every time solo. And yet the mage does well enough against the rogue. RPS.
Different styles and I probably will do a mage (or priest) this time around but I would not be messing with Locks if I don’t need to typically.