No, I didn't file a bug because my guess is that it's a design problem, that is not something that you can fix in any simple way. The problem is that every time that you select a virtual desktop, the windows in it are displayed in real time and that IMO eats huge quantities of cpu when you have many windows open, even if they're dormant (I may be wrong obviously, it's just a guess). Couldn't they take snapshots of the windows at some interval and display them? They could have been even cached that way. Is that impractical or maybe I'm missing something obvious for some reason? Even better, why not just show a little part of the title and nothing graphical at all? Not enough fancy stuff?