My problem with this is that it looks too similar to a CPU heat/component map. And, frankly, the actual layout in treemaps is basically arbitrary. Indeed many

My problem with this is that it looks too similar to a CPU heat/component map. And, frankly, the actual layout in treemaps is basically arbitrary. Indeed many early "disk utilization" charts that look a lot like treemaps were entirely based on physical location on the disk. As such, the logical layout was not on display, and you were only able to see the physical layout. Which was usually important, as you could see if there were obviously bad sectors or if fragmentation was out of hand. That is, the very concept of "neighbor" that treemaps show is completely logical in nature, and doesn't really indicate any physical neighboring relationship at all. I suspect that is why I'm not a huge fan of them.