So, I'll open this thread and probably end up expanding this post, since I'm only going to write about the few negative aspects I experience since the update.
1. I play in windowed mode, so after the update the resolution was at max and in windowed mode which wasn't surprising... happens often after updates I guess. The annoying part is that now with the selected resolution the upper left corner will be centered on my monitor, so I have to move the window quite a lot every time I get into a game.
2. Maybe It's just an illusion, but champions at the border of the screen appear to be even more sluggish than before, it looks like it's skipping a big ammount of frames on the animation of champions at the border of the screen... before this update I slightly noticed it, but more on minions I think.... but now It's on such an extreme level that I cannot ignore it.
3. Fiora's Passive update: I allready had a bad feeling when I read about it... I haven't played her in a while but I'm pretty sure that I did play her atleast once in 6.1 . The indicated vital direction spawned by the passive did not concearn me, it usually was right between me and the enemy, often at the sides so I have to use Q... rarely behind. Now now, I've just gotten her in an ARAM... and most of the time the indicated strike direction was behind the enemy champion... to successfully strike that I would need to E Q Strike Strike to hit the vital for once, which would however expose me in a very strong way.
Seriously: that's really unsatisfying.