After doing some tests on the R390 I found that with some more advanced settings the GPU would max out a 100% and then I would get the jerky motion when looking around. The CPU never went higher than 60%. So I changed out my AMD R390X for a GTX 1070. Man that is one big friggen card. Since I have moved up to the 1070, the max I have seen for the GPU is 92%. I get no jerky motion. I can set the resolution to 4000 x 2221 which is fairly crisp. What a relief. Things were smooth... but I couldn't leave it at that...
So... I decided to spice things up a bit with the ORBX global and vector modules. I thought this might reduce the load on the GPU. However it seems to have increased the load (which makes sense now). There may be a way to tweak the settings. I now have an annoying flash, just like blinking my eyes, which happens randomly about every 3 to 5 seconds. It increases as the scenery gets more complex. The GPU still maxes out at 92% the CPU is still low. I can see in Steam VR that there are many missed frames. I am not sure of how to troubleshoot this further. When I decrease the scenery complexion The flashes slow down to 1 every 10 seconds or so. The flashes are much less painful than the jerky motion but still annoying nonetheless. If anyone has any ideas of how to go about fixing this please let me know.
PS I am not getting the black flashing so maybe Steam has fixed that problem.