Just finished the game yesterday. Didnt noticed any performance hits, but i was not playing with unlocked FPS so cant really tell. My problem was with rockstar DRM called Social Club that straight up refused to let me launch RDR2 that i bought on steam. All atempts to contact rockstar support ended in failure, Steam also refused to issue a refund cuz i bought the game more than 14 days ago. I managed to find a crack to bypass the rockstar launcher but i cant launch the game from Steam, need to use the launcher.exe included with the cracked files. (This mean no steam achievements, cloud saves, no Dualsense support, or online play)
Its ironic that these DRM are only hunrting legit buyers while ppl can just pirate these games and have a better experience for free. Now i know i cant buy any more rockstar games from steam, cuz they will not even launch.