Seriously over 50% of the games I play have a vayne in them. I don't mind that she has no weak point at all during the game and is always strong or the fact that I personally do not like her. It is the fact I am bored out of my mind playing against her for the love of god disable her or something for a week so I can see a Lucian or any other ADC.
She does have a weak point, actually: Lack of range and a slow start early on.
Playing champs who can outrange or go aggressive against her early (Such as Caitlyn or MF) is recommended to keep her from snowballing.
With that said, compared to other "weak early game" ADCs, she has way too many safety options in her kit and her power spikes are brutal. That's really the only thing I want to see addressed with her.
You see Vayne every game how about me seeing this cancer 
every game?
The change to Energize stacking was a significant indirect nerf to Vayne.
I'm curious if her strength will pick up when people start running Trinity on her rather than Shiv (Trinity/Cannon/Tumble is a pretty potent opening salvo). But for the time being I would say she's probably fine.
