It's sometimes useful to have a panel which is a bit thicker than the default, in order to fit in more stuff. In particular, to have two rows of window-buttons
in the taskbar. But:
  * To get a double-row in the taskbar, the panel must be really extremely large. It should be possible to make the taskbar have two (or even 3) rows independently of the panel height.
 *  When the panel is taller, the other applets do not stack, but they just grow. So we get lots of wasted space, and some very ugly stretched icons. It would be better if, for example, the battery and speaker icons in the system tray remained small, and appeared in two rows.

Other information:
KDE3 gets this one right. It's especially important on a laptop with a small screen.