It is pretty apparent right now that he is overpowered, but let's not repeat what happened for the third time in his lifespan now: Aatrox becoming good then wave of nerfs putting him in the duster for months straight.
The hotfix came along at a point where most people didn't know how to play the new Aatrox and his core items that he should build given his new kit. It brought changes that were needed, yes, like the armor and passive damage boost. but what was unneeded and what boosted his winrate way too much is the Q damage buff. He simply didn't need that damage buff, even less so since his mini-rework already buffed his Q damage by quite a bit. So, before nerfing Aatrox for things he didn't do, please consider just reverting the Q damage buff hotfix.