Aatrox Needs to be buffed
First let me start off by saying this: I know that there are planned changes on the PBE to potentially buff Aatrox
With that out of the way I'm also going to say that only the Q change is a buff more than anything an extra 75 units when he ults is not going to do anything if at all much. What Aatrox needs the most more than anything is more base attack speed, the thing with Aatrox is that he needs as much attack speed as he can get because it's his only way to even proc the heal/damage portion on his W. The pro's of his old passive was that when he stacked it up to full you got the attack speed you needed to even be a relevant champ whether you were playing him top or in the jungle.
As far as I can tell there was absolutely no reason to touch him back in 7.5, he was more towards the balanced end of the spectrum rather than the Underpowered or Overpowered ends. His passive was much more reliable since his blood well wouldn't just start to immediately drain when it capped out, the new passive changed him from being consistent DPS to inconsistent burster who can't even 1v1 most top laners. Sure the extra 25% base AD is nice if you build a trinity, which is almost never since the item is quite expensive for what aatrox actually gets out of the item. I would rather have the plain attack speed and reliability from his old bloodwell rather than the new passive's conditional attack speed and bonus base AD.
I'm going to reiterate this for all the aatrox players out there: The current passive does NOT feel good at all, it only pushed him further towards the underpowered end of the balance spectrum.
One final note that I have is that I want the Balance team to actually look at the work they've done, look at the feedback from those changes from the groups that have the most knowledge in that area you changed. Are they saying the changes were good or bad based on the gameplay they have done with it? Listen to your community, this game was made for the masses not for a closed circuit of people who want things to be changed at their whim's.