Well done in general. Kinda useful feature. All flickr stream version sucked. BUT! The script has needed to be updated since flickr switched its experience last year. And a new version is actually upcoming. Was the add-on completely left out of support at all? Or this to be fixed if desired or requested?
IF, you find that button sitting on the toolbar (It was'nt there, the first couple times, I restarted FF! And, somehow, it appeared), the button is way T-O-O B-I-G! Using FF on Mac with wonderful small theme, so the button kills my design. Flickr is about Art, the button sucks.
The feature to view the most popular photos in a group is best! I use it every time I find a group I like, and it's helped me to find some of my favorite artists. Also the fastest and easiest way to scroll through a group's images at medium size. Thanks!