Truly great, capture selection, capture whole pages, copy to clipboard or export to pdf or jpeg.
Only thing it cannot do is capture those floating windows within windows (like for example facebook picture that you open when you click on the picture in the home page so it hovers above the home page. It would captue the homepage behind the floating windows. So for that I use prntscr)
But all else, this one is the best so far.

This Add-On works pretty good and does exactly what is advertised...it makes screenshots ;)

A nearly perfect tool for capturing images and full pages from the web. The only way to improve it would be to add a save to ebook format.

outstanding add-on. Saved me hundreds of hours in getting snapshots. Thanks. Bravo !!

Great addon with really useful options.

Wonderful add-on that helps me to document the corresponding results when doing research on the net.

This is a very simple and very good extention. It made our life very easier and quickier.

Very good for taking entire webpages (visible and in-visible parts of your screen). Easy steps and wonderful work flow (quite a few useful settings) for what I use it for..

Great for sending clients screenshots of websites before live and also working with Tech supoprt to show issues. Recommended +++

Very useful I could not do without it :)