I have one, and it's an amazing laptop. However, as Purism are focused on privacy and free (as in freedom) software, they won't put in a gpu.
System76, for me, seems to have a balance between coreboot and as much free software as possible. But also the addition of a proprietary blob full gpu.
Also the system76 cpu specs are slightly higher.
https://puri.sm/products/librem-15