I have a RX 6600 XT and it was a PITA in many instances. Sometimes black screen at boot which resolves after GDM is started. Freezes when waking up which is an issue that come and go on Arch after each update cycle. Bizarre frame drops in games out of nowhere. Like one day I had stable >60fps but next day after a reboot with no change to the system it stayed ~15fps. This was a huge pain for almost an year after launch but I think it is stable enough by now.
