I bought it in paper because it has maps. They are not color maps. They aren't particularly necessary maps -- you could look online at other maps and they would work just fine. But it is sort of handy having it all in one place, and with somewhat appropriate granularity and so forth. Map making is always a set of choices about which geographical and/or political features to include or exclude, and those are important if your entire thesis involves political geography or the geographics of politics or hegemony or whatever you care to call it.
Like all arguments that purport to attribute a large sweep of human behavior and/or history to a comparatively simple aspect of the physical world, Marshall's arguments get very bogged down in the details. But like any good argument about the influence of physical reality on human behavior and/or history, there are a lot of good insights here. The main problem is that the overselling isn't limited to the subtitle (Ten Maps That Explain Everything About the World).
But if you've never read a breakdown of the various regional hegemonies the predated the Cold War duality, and which have risen to prominence once again, it's a reasonable introduction and it slides by fairly quickly. I didn't put it down because it was bad -- I lost it in a stack of papers. If you already have a sophisticated understanding of, say, China's involvement in the global South, then you'll gain little from this. And depending on how old you are, you might be kind of disappointed and/or confused by the flippant handling of things you remember from your youth, like why East Pakistan is now Bangladesh.
If you know of a better book on a related topic, I'd be interested in it.