Moving windows in compiz can be quite slow in a restricted hardware like for example a virtual machine that doesn’t use hardware acceleration but software rendering. When a window is moving, the area behind it is invalidated and a texture is filled with the window content and all that is composited and send to the GPU (or the CPU in case of software rendering). In order to reduce the overhead of these operations plus the overhead of visual effects like blending (used for transparency), we added two new options that are significantly faster: outline and rectangular mode (see video above). Enjoy!
Life saver!