Works very well for me! YMMV maybe depending on the titles you play, but that would probably be more of a Proton issue than an AMD issue, I'd guess. I'm not a huge gamer, so take my experience with a grain of salt. But I've racked up almost 300 hours of Witcher3 with the HQ patch on a 4k TV display using my self-compiled Gentoo kernel, and it worked totally fine. A few other games, too. So there's that!