The AMD drivers are open source, but they definitely are not good. Have a look at the Fedora discussion forums (for example https://discussion.fedoraproject.org/t/fedora-does-not-boot-... ) to see what happens about each month.
I have no NVIDIA hardware, but I understand that the drivers are even worse than AMD's.
Intel seems to be, at the moment, the least worse compromise between performance and stability,