Very good and feature-rich screenshot add-on. The post screenshot editing is awesome. I love it and use it over Firefox's built-in screenshot tool..

One thing that needs improving is that the Button's drop-down menu with the different types of screenshots does not remember my configuration (i.e. the less-used buttons I remove annoyingly reappear).

Also, sometime the area I selected is not the area the resulting screenshot is of. It could be a hard-to-compensate-for CSS layout issue of the webpage.