I have played around with screenlets. Very nice, but nothing functional enough to grab me. But, AWN is something that looks good and I find very useful. The dock is stable and has good properties management. And there are now new applets being added at a rapid rate. New applets added in the last few days include a volume applet, CPU-meter applet, and GMail checking applet. The awn-extras also include stacks (think file system browser) and a main menu, which gives you access to the Ubuntu applications menu. And now you can also theme AWN.