At this point, I don't even know what to say that hasn't already been said.

A very large portion of champions that have been buffed this season have just been nerfed right after, and vice versa. Regarding overbuffing, you've got many of the new/reworked champions, like Swain, Kai'sa and Zoe. Regarding the latter you have a lot of the meta picks at the time, like rammus, leona, shyvana and twitch.

What frustrates me is the fact that the smaller changes in the game have made a significant enough difference to a champion's performance. Just trimming Warwick's base AD and his Q ratio lowered his win rate, and though he's still on the stronger end of junglers, he's less of an issue. When Volibear was changed and was powerful, he received a small nerf to his knockback duration. Skarner was strong for a while, and they reduced his stun duration slightly. On the other hand, a slight buff to Graves (health per level and ult CD) was enough to convince people to play him again, and he's performing quite well again.

It's not limited to champions either. Press the Attack got nerfed and then buffed right after. Aftershock got changed to cater to fighters, who don't even run it now. After 8.11, I'm guessing Lethal Tempo's gonna be popular. The problem is that it already received a sizeable buff, and after ADCs powerspikes are shifted to later in the game and Fleet Footwork gets nerfed, it's probably going to be a lot more devastating.

Ideally, I'd like for nerfs and buffs to be more gradual. Too many champions are left in the dust for too long, rather than getting small buffs to keep them going until bigger kit changes take place. That being said, I'm not holding out hope that anything's going to change, if the last mundo buff (and upcoming nerf) is anything to go on.