Perhaps the Questline is not too slow after all. Sorcerer's Gambit has been featured quite prominently across many early decklists. Americas Grandmaster NoHandsGamer was seen trying out this version on his stream while fighting for top Legend ranks. 

Hey, you know what everybody's been talking about all over again? Nerfing that card called Incanter's Flow. If you are good enough, you are bound to draw it by turn 2 - which apparently helps with winning matches decisively.