A few noticable Gameplay changes that may help:
1: Kalista: Have her bounce no longer interrupt In Progress Attack Animations. If Something has fired at her, or swing at her, and it is already halfway through the animation, her next bounce should not cease this action. I notice I still get hit as Ezreal if I Arcane Shift mid attack (and he is magically warping through space).
Accomplishes - Kalista's endless immunity to most other ADCs and Melee champions would level back off. Still hard to get in range of, but once you close that range you can at least hit her once or twice before she bounds away again.
2: Sion: Fix him. Right this time.
Accomplishes - You wanted an AD Bruiser, so you took away his ability to become an APC that out farmed and nuked most of your designed APCs. This didn't mean beat him in the head with already existing skills from other champions that aren't their most effective in their kits. You've made a Tower Charger.
3: Rengar and Kha`Zix: Why does it almost feel like we're playing the same champion? I can burst you, slow you, and heal myself... these are my only real purposes. If it comes down to it I'll go invisible for a second to chase or run. If we're going to have different animations, at least let us operate differently. The same masteries/Runes/Build can work on us both for a reason.
Accomplishes - Now we have two champions that are more than minorly different.
4: Riven: Is there a particular reason that this incredibly bursty, CCing, Tanky woman shields herself too? Please excuse your tower starting at level 3, it won't help you.
Accomplishes - Players are no longer playing the 'Avoid Contact At All Costs' game at top, and she doesn't have an instantly secured escape from most ganks.
5: Black Cleaver: Well, now it's a staple item for most AD champions, not so much because it makes you tougher and hit harder like it used to... but now the bruiser is glued to your carry. Alterations like this are why the Tanky Meta has come back. It does me very little good to be able to burst your skull in if I can't get you off of me... aaaand now you hit like me too. Vayne Forever?
Accomplishes - Being fast used to be a trait of assassins and carries, and those bruisers and tanks that wanted to catch me had to either time it properly, buy boots that only really enhanced this ability and not others, or grab me at a distance. Gap closing only has to be done once if, once I catch you, you're stuck with me. Between Cleaver and Warrior Enchantment you've lost your ability to effectively get away from a jungler or bruiser, even with an escape mechanism.
6: Luden's Echo: Since we've made a tanky meta, let's ensure that anyone that can go AP will now hit you roughly 10% harder. On most champions this is a non-issue, and it is a rather nice item... but on champions that are simply going to take a SpellBlade item on principal, why is it that we've handed them yet more damage to stack on skills that will proc On Hit? It has reached a point where AP GP is nearly more effective than AD, and while he does not have the sustained damage, he can still duck in, make your carry disappear, and wander off at nearly full health. A simple fix would be to adjust the item parameters so that it no longer procs on skills that apply On Hit abilities. We have an item for this, it is called Spell Blade.
Accomplishes - No more Luden's/Spell Blade stacking. Champions that run Spell Blade tend to hit incredibly hard as it is, and the combination can turn almost any champion into a bursty APC... even if they get no bonus for using AP.