I don't think the changes to the 3d preview are an improvement from when i razed this topic before (see link below) .
Again there is very little tonal contrast on the modal itself, making it look flat and again this lack of contrast is exacerbated by the high contrast of the white background. I also think having a black grid on a white background makes the grid far to prominent and draws attention away from the modal itself.
If it was possible i think the best solution would be to create a 3d preview that allowed users to set their own display preferences for colour, tone, toggle grid etc.
The best 3d preview ive seen is on MyMiniFactory, they also have a cross section view option which is a nice extra.