Comment 23 for bug 334809

One example I've run into most often: the music player QuodLibet (with notifications plugin enabled). Try playing an album, and then skipping forward or backward about 5 tracks.
What happens with notification-daemon: all the notifications pop up at roughly the same time, and then shortly disappear.
What happens with notify-osd: the bubbles tie up the desktop so long that you no longer have any idea which track you're on.
It's especially bad if you try to skip back when you're already at the first track -- it still shows a new notification for that.

Another app that may be taken as a torture-test: service-discovery-applet. Try adding one to the panel, enabling discovery for all services, and enabling notifications. On joining a busy network (such as one at a library), this can generate a ludicrous number of notifications all at once. With notification-daemon, it spams them all at once... but with notify-osd, it ties up the notifications for a very long time.