I think that’s PWM dimming vs DC dimming.

PWM dimming turns pixels on and off to make them darker. So for 50% of the brightness, it’s off 50% of the time. Higher end panels flicker much faster which helps mitigate perceived flicker. I think 500hz and above is preferred.

For DC dimming is just using voltage to control the darkness with no flickering involved.

I have a 7840U with a 55HWr battery. I can squeeze out 7 hours. If I’m power using then 5-6 is typical. With the 63WHr battery, you’ll get about 15% more time with it.

I want to be able to upload/download/share my photos from anywhere in the world without using a VPN. Additionally, this satisfies the wife requirement. It works in the background without her needing her to turn on the VPN. I don’t want her to keep asking me how do I turn on the VPN? If it’s just me, then no issue, I’ll use a VPN.