If you want an excellent VR experience with P3DV4 - here is a starting point:
1) Download the BlueSky photoreal scenery for the Grand Canyon - not necessarily all of it
2) Use the Alabeo Extra 300 and fly down just above the Colorado - FPS single monitor >190 and locked at 90 in VR
3) Graphic settings - mostly standard except:
- 8XMSAA, No FXAA, Aniso = 8X, LOD = MAX, Water Detail = LOW, No Reflections, HDR = off, No dynamic Refl/Lighting
4) Shadows = LOW, Clouds = minimal, no traffic , Vsync = off, Target Frame rate = unlimited
5) Use Oculus Tray Tool by ApollyonVR http://bit.ly/2s0vsDS
to set Pixel Density = 1.5
Then, after enjoying that, try other aircraft and you will see that many of them cause a significant slowdown. The best in addition to the Extra include the F22, the Cessna 172, the Maule, and the Blackhawk. Then try small airports and finally complex airports and the single monitor framerate will be below 60 and therefore the VR experience will be very poor.
For some reason, P3D/FSX/ESP always has had a framerate about 40% that of War Thunder, Aerofly FS2, and Combat Air Patrol - all of which generally maintain an FPS >200 (i7 @ 4.2Ghz, Nvidia 970) where there is similar graphical content in terms of terrain + objects + instrument panel graphics. FS2 usually can do >300 fps with an electronic cockpit and a complex airport like KSFO. I am hoping now that Lockheed Martin is using source code that is 64-bit that they own and understand, they could increase performance to that of the other flight simulators. The other sims show that it can be done.