Vertex paint mode needs optimization

Nowadays when we start having very advanced sculpting features in Blender, I think also the vertex painting mode needs some optimization and maybe additional features later when it works without lag, but that's another topic.

The sculpting mode works very well without lag with meshes that has around 5 million polys. At that point you have so much details that you could draw very detailed vertex paintings to be baked later in textures. However, the problem is that the vertex paint when having so many polys is lagging so much that it's very hard to use for painting.

For example in zbrush, the vertex paint is very commoly used for texturing, so I think Blender would benefit from that also.

Skin details done with mixed vertex paint and generic skin texture and AO bake: