Water Detail: Low
Shadow Quality: Off
HW Vertex Processing: Off
Multi vertex System: Off
I did NOT change the core affinity to a single CPU
I tabbed back to windows and STOPPED the Run.exe that launches with the game
I forced the lack of antialiasing in the nvidia control panel but I don't think that'd make a difference.
There's still the occasional flicker here and there but well within bounds of playability. Most importantly, there is almost no slowdown in the city or when in the hovercraft. I had a bit in a cutscene but not too insufferable.
I also updated my video drivers with the custom cfg versions from laptopvideo2go, good if you're on a laptop, presumably less so for other people.
Hopefully this will help someone else.