I have run up against Mental Misstep in playtesting, and TBH, it isn't the 'bane of the format!' or any such nonsense. Is it powerful? YES. Is it overpowered? NO.

Zoo can still fight through MM's like they fought through Force of Will...if you haven't noticed, zoo has been gradually 'curving out' better over the past year anyways with Green Sun's Zenith and playing up to a full set of Knight of the Reliquary and sometimes Terravore.

Mental Misstep punishes sligh decks, sure. But there was ALREADY a plethora of cards that punished sligh decks (Daze, Force, Spell Pierce, Spell Snare, Chalice of the Void, Trinisphere) It's just another powerful weapon in a powerful format...get used to it.

The u/g infect deck played Mental Misstep correctly...it was there to protect 'bad' cards like Blight Mamba and Ichorclaw Myr. It was also a combo deck...not really an aggro deck. He was trying to combo into 10 poison counters, not attack from 20-0. Berserk Stompy is already tier 2 (at best) and that has 'good' cards like Silhana Ledgewalker and Slippery Bogle. I don't see this as an argument for MM in aggro decks. I see it as a way to shore up tier 2 decks like Berserk/Infect stompy and give them at least a minor leg-up in power level.