Rated 5 out of 5 stars

Great extension but it needs 2 improvements:
1. Most people use *smaller* statusbar - there should be a 16x16px icon for statusbar. The one included now makes statusbar unnecessarily big... I've just replaced the logo.png with http://simplest-image-hosting.net/png-0-toolbar-replay-icon-16x16 but a more universal default would be nice.
2. It would be great, if the extension would indicate on/off by changing the statusbar icon (eg. color). The alert() method is not really perfect.
Anyway, it's already the best extension for looping YT :-)

This review is for a previous version of the add-on (1.0.2).