My problem with such tools as that it always looks nice on toy examples but when faced with some real-life complexity the source seems always way more clear and faster to navigate.
Naturally, you can't get rid of reading source code, that's where all the information is. But the visual representation can speed up navigation and understanding a lot. Having worked with the visual navigation of Coati for while now, I can tell you that it changed the way I develop software. Seeing at a glance which classes derive from an interface or where and how often a function is called gives you a whole new perspective on your codebase.