High 3D-spatial ability and navigation does not necessarily mean fast processing of 2D info like street maps

This is very interesting because you might assume someone really high in 3D spatial intelligence could just look at a street map and figure things out in a few seconds. But actually, a street map is 2D whereas the 3D brain wants objects to "turn" in the mind, so they might be slow in processing the 2D map.

Having said that, 3D brains would be best at processing 3D maps and models -- like elevation models.

Without question 3D spatial ability is best when it comes to actually navigating yourself through a city--not on a street map but in person like in a car, or flying a plane through clouds, or even weaving your body through traffic in basketball. This is 3D navigation.