[improbable22]

It depends a lot where you go. In places like Nepal OSM is often better than any map you can buy. In the Europe and especially the US, it's not as detailed as the national maps. They usually also have much better contours (drawn from aerial photos not from the space shuttle).

But still much better than Google maps, which seems very much for cars (at least outside of cities).

[Mediterraneo10]

Most of the aerial imagery used in Europe for improving OSM is shot from planes, not from space.

[improbable22]

> Most of the aerial imagery used in Europe for improving OSM is shot from planes

Yes I know, and not just Europe. But my comment there was specifically about contours, i.e. height data from SRTM. I'm not aware of any project to crowd-source stereo-pair contour drawing, but if you know of one, I'd be interested to have a link.