As I wrote, it's very subjective. I've been working at 40 Hz for 2 years and I didn't notice the difference. I press windows-fn-F9/F10 instead of only fn-F9/F10, not a big deal. Automatic brightness control as on phones? I would probably disable that anyway.
By the way, brightness control didn't work in 2014, then started working, then it stopped working again. Kernel versions / NVIDIA drivers, who knows.