After playing for a few hours I'm playing mostly on the high preset, with AF increased to 16x and my frame rate is solid, I've disabled VSync and capped to 70fps with RT and that has given me the best results, no more jittering and only very minor tearing, I hit this cap 99% of the time.
I have crashed a few times though, just now for example while doing the Firing Range, a quick Google search shows I'm not alone with this area causing problems, you'd think by now it would be fixed, that's usually one of the benefits of being a patient gamer.
Edit: Running through the city gets choppy, it's like asset load hitching. Normal gameplay is still solid.
Edit: 10 hours in and general gameplay is great but Prague runs like ass, the frame rate will plummet to 30ish for a couple of seconds then shoot back up, it's definitely a loading issue. SSD + 16GB RAM should be enough not to deal with shit like this.