I will only talk about Zed because i don't give a shit about the rest.
Zed's Q AD scaling went down by 5%
E cd went up by 1 second. Base damage at rank 1 is 70 from 60, so i am guessing the other ranks also have more base damage probs to a rank 5 of 180 base damage as in live, i am not sure yet.
W lost the AD passive, refunds 10 more energy on double ability hits.
Ult damage has stayed the same, regardless of the changes that were made to Duskblade. The AD passive that was removed from W has gone over to R but with significant nerfs and changes. It gives Zed 5 flat AD at all ranks, plus 5/10/15% at ranks 1, 2 and 3. This AD is taken from the target killed with the highest AD on the enemy team. Why is this a nerf you ask? Well, it's less than it used to be on W and also it depends on what your enemies build, which can easily be turned against you. The enemy team can pick an On-hit based ADC that doesn't build a lot of AD, and the rest of the team can be AP based and tanks that also don't build much AD. Now, this is the stupidest thing ever to be introduced. Your performance and damage output will rely on what offence your enemies build. Totaly not a nerf, huh? Not that to get the same AD that you'd get now, the target must have a not more AD than what you need to build now.
For an example of that, my build is 335 AD from item. So, the W passive gives me 67 AD. To get the same, my target mus have 413 AD. If you are not a Jhin, Rengar or a fed talon, no, i will not get even half the amount i get right now. If you are Jhin, your supp will be with you and if you are smart, i won't manage to kill you, if you are a rengar, you will probs kill me instead, and if you are a talon with that kind of AD, i will die before i can cast W.
Zed is gutted, and with the flat armor penetration changes, it's even worse. Why? because riot is bad at what they do. Flat armor penetration wasn't problematic. The abundance of flat armor penetration and the massive AD values we get so early into the game was what caused the problem. All while APs got to keep their beloved void staff last preseason and now they also get to keep their magic penetration.
Riot is doing one good thing only to mess up everything else. And yeah, thanks for SoloQ but, you don't get huge credit for correcting your own mess.
Oh, and btw, why does rengar gain 30% AD no matter what level he is, only based on his unique kills/assists while zed gets to lose his 20% that ONLY GOT AT LVL18? Is this what you call balance? Is this a slight number tweak? No, it is a massive nerf. Just the fact that you made Zed have his power depend on how his enemies play and not how the zed player plays and acts is toxic and unhealthy for the game. What are you doing Riot? Is that what you meant that Zed was the model of a healthy assassin? Is this massive nerf what you call Improvement? Is this healthy champion design the reason you take away his power only to give a similar stat on STEROIDS on someone else? You remove Zed's passive 20% AD that only has access to in the late game, only to buff it by 50% and give it to Rengar and also make it available as soon as he gets 5 kills/assists, 1 for each enemy champion?
Really riot? Is this what you call balance? Is this what you call improvement?