I would disagree.
The phone behaved perfectly on KitKat. Tremendous battery life. No freezing, no lag. I had my core apps that I always rely on.
The freezing, crashing, loop of black screen followed by freezing that can only be remedied by battery pulls, camera freeze, inability to load pictures to FB, FB crashes all began after Lollipop. None of these issues were present when I first got the phone. And I have added no apps since Lollipop.
Therefore it's not the device. It's the OS.
Sent from my gorgeous sexy white BEAST of a Note 4 ❤