On a complex model TestMaxSpeed redraws 100 frames at 8.14 seconds, and if I extract the rendermesh and hides all the Nurbs it does it in 2.93 seconds.
That is almost 3X as fast in the mode that is most important for visual evaluation of the design.
Three times as fast with the same visual quality. Or I can have a scene that is more than 3X as complex.
And if I join together some of the large meshes with the same render material (So the total amount of parts goes from 479 to 245) then it drops from 2.93 to 2.15 seconds. That is almost four times as fast!
To me it makes a LOT of sense to make a rendered display mode that when ever redrawn hides all nurbs data and just show the rendermesh. Then calculate the nurbs info when the display mode is idle.
It would also make a lot of sense if AA had the option to be only redrawn when the view is idle. As a speed up option when FPS drops below the current limit.
This is the scene I used for the test. A converted V4 file with updated materials and a HDRI environment. Rendered mode with shadows. 8XAA TestMaxSpeed ran at maximized view on a FullHD monitor.