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.
[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