For a long time it has bothered me that Compiz does not seem to run as smoothly as Metacity on my desktop system. With desktop effects switched off, moving windows around the screen would seem smoother. With desktop effects switched on, I’d also notice tearing in areas of the screen with fast motion including in videos. I was fiddling with Compiz settings recently and managed to fix the problem entirely. Now, if your graphics card struggles to run Compiz this will probably not help you. But if you have a decent graphics card (mine is a nVidia GeForce 8600 GT) give this a try if you have noticed this problem.