I upgraded from a Geforce 460GTX to a Radeon RX560, and I ran into two issues. Nothing major, and I've had worse issues with the Nvidia drivers, but they are still something to be aware of.
The first was that my distro (KDE Neon based on Ubuntu 18.04) shipped an older version of Mesa at the time, which was too old for the AMDGPU driver, so I had to add a PPA with an updated version. Since Neon updated to a 20.04 base, it works straight from a clean install. It also worked with no issues when I switched to openSUSE Leap 15.2.
The second was that DVI output was limited to single-link instead of dual-link. My monitor at the time only supported full 1440p through dual-link DVI or displayport, and the old GPU didn't have displayport. Buying a displayport cable was a quick fix, and I believe the DVI issue is fixed in the driver now.
Aside from those two minor hurdles, it has been smooth sailing, very good OpenGL performance in the games I play.
The first was that my distro (KDE Neon based on Ubuntu 18.04) shipped an older version of Mesa at the time, which was too old for the AMDGPU driver, so I had to add a PPA with an updated version. Since Neon updated to a 20.04 base, it works straight from a clean install. It also worked with no issues when I switched to openSUSE Leap 15.2.
The second was that DVI output was limited to single-link instead of dual-link. My monitor at the time only supported full 1440p through dual-link DVI or displayport, and the old GPU didn't have displayport. Buying a displayport cable was a quick fix, and I believe the DVI issue is fixed in the driver now.
Aside from those two minor hurdles, it has been smooth sailing, very good OpenGL performance in the games I play.