i7-8750H or 8850H for Lenovo X1 Extreme?

[modeonoff]

Hello, I am going to buy an Extreme. The 8750H version comes with FHD screen while the 8850H version comes with 4K touch screen. Does 8850H performs noticeably faster than the 8750H? How about battery life and heat/noisy fan/thermal throttling between the two CPUs?

 

[rgd1101]

MERGED QUESTION
Question from modeonoff : "Which CPU for Lenovo X1 Extreme if I don’t want noisy fan and other thermal issues?"

I am planning to get a ThinkPad X1 Extreme but in my city, they don7t have the i5 version yet. What are they practical differences between the i7-8750H and 8850H versions? Which one do you recommend if I don’t want noisy fan, uncomfortable heat on the laps and hand rest areas as as well as thermal throttling issues?

 

[hang-the-9]

I would not get 4K in a laptop screen, the display is too small for such a high resolution. For the CPU speed difference, there won't be any that you would notice.

 

[modeonoff]

Is scaling, say at 150%, a bad idea?