I have the same laptop with the 4K IPS display and the AMD 5850U, and I am pretty happy with it.
On Ubuntu I had to install the Wi-Fi driver manually [0], tweak the grub config to make the screen brightness control work [1], and install gnome-screensaver to make suspend/resume work properly. Maybe things would work better out of the box on Pop!_OS?
Otherwise, it's pretty good. It does not heat up much compared to the previous Intel laptop I had, and it is plenty fast.
I was not able to make Howdy [2] work properly, and the fingerprint reader was not reliable compared to my MacBook, however.
The wifi issue was pretty much what made me give up on the Thinkpad and go back to the Macbook, where I can set up my work environment pretty quickly and not have to deal with other random issues…
[0]: https://github.com/lwfinger/rtw89
[1]: Add this to the grub file : GRUB_CMDLINE_LINUX="amdgpu.backlight=0"
[2]: https://github.com/boltgolt/howdy