Why is Neon more responsive than Rendered view?

I know this is REALLY comparing apples and oranges, but when I work on a huge file on my dual cpu workstation it is faster to navigate the scene in Neon than in Rendered mode, and that just doesn’t make sense to a layman like me, so I wonder if there is anything the Neon pipeline could lend to the OpenGL pipeline get rid of it’s bottle neck so it could use the GPU’s full potential.

To me Neon can not replace OpenGL for modelling and I am very keen on letting my hardware work as fast as it can when working on large and sluggish scenes.