Rated 4 out of 5 stars

StumbleUpon is just great, and the toolbar is the perfect app to waste hours and hours of surfing the webs... its functionality might be better, and I can confirm a certain slowdown & stability issues, but overall, it is a must have for stumblers.

This review is for a previous version of the add-on (3.76). 

Rated 5 out of 5 stars

Until today, StumbleUpon seems to me the very best tool to discover the internet. It is easy, comfortable and addicting - you may experience the web like never before.

This review is for a previous version of the add-on (3.38).