I am not surprised that there is a top-like tool for monitoring the X Window system. After all, there is a plethora of *top tools aimed at any aspect of your hardware or information flow, and X is not that special.
On the other hand, the fact that xrestop is intended to run in a console is ironic at the least. 
I know it works, but I also think that most any text-based tool works smoother than something running under X, the slug. That’s just my generalized opinion, and I’m not bashful about it.
But a text-based tool that gives readouts on X system demands is far too ironic to leave alone.
xrestop itself is not in any way disappointing or flawed — in fact, it does a great job showing what is running, what is taking up time and what is most demanding on any particular display. It can accept specific display addresses and report on those, adjust its refresh delay and a few other options through command flags.
All in all, it’s at least as good as some of the other top-esque tools that are out there, aimed at other aspects of your computing experience.
Still … I would have expected something … well, graphical. After all, doesn’t a graphical load monitor aimed at the graphical subsystem just … make sense? 😕 Maybe not.
Inconsolation 