The application usually performs well, menus are responsive and visuals are quick to refresh.
This can be seen for any animation: play button, timer, oscilloscope, list navigation...
When either hovering over the winamp item on the main toolbar (winampPreviewBug0.png), or when using the alt+tab menu (winampPreviewBug1.png) the performance of these visuals becomes poor, and menuing becomes sluggish.
Sample video is also attached for clarification.