I patched last night - XBone - Went into single player and the frame rate is so low I nearly got sick. There has never been an instance where I got motion sick playing a game or watching a stream, etc. Camera Movement was choppy and riding a horse was almost not possible (running into trees, could not stay on the trail, etc). My wife enjoys watching the game but does not like to play. She came into the room and told me she could not even watch the screen (We have a projector with a 10 foot screen)
This problem does not occur with any other games and it was not like this at all before the patch Tuesday Dec 11. I submitted a ticket to Rockstar but, really don't expect a response. This does not seem to be a widespread issue as far as I can tell from searching. I did create an account here to post a response to say I am having problems like that too after the patch. I haven't tried online because I wanted to finish single player first.
I will give it a couple days but, if Rockstar does not respond, I will try a reinstall. The thing is, I really really don't want to risk losing my game saves. I know it gets cloud backup but, I have no idea if the local uninstall will remove the saves or not.