I tested Version 3.0.21 (Last Updated: June 22, 2017)
on Firefox 54.0.1 (32 bit) on Windows 8 with 3.5 GB memory.
It installs Ok.
The first page I tested it on was 4chan's Comic and cartoon catalog, not particularly large with small thumbnails.

Problem 1: the addon slowly scrolls down the web page to complete its capture
Problem 2: the browser locked up for a good 5 minutes while the addon was (I guess) composing an editable screencapture in a new tab.
Problem 3: I noticed data was being downloaded from a third party website. Why? Will this work offline like other page savers?
Problem 4: once the capture was complete the cursor changes to a kind of paintbrush and the browser ran very slowly.
Memory use reached 3.5 GB.
I had to control-alt-delete for two minutes to regain my task manager and then able to close the Firefox tab with the editable capture. Browser and computer return to noemal operation.

Clearly something needs fixing here.
Pearl Crescent Page Saver does not do this, it just captures the whole web page and saves it in a file.
I use Pearly Crescent in my other Firefox profiles with no problem.
Pearl Crescent Page Saver does require a restart however, which is why I tried this "Awesome" one.

This might work for some people, but such an initial experience is enough for me to swear never again.

This add-on does not capture the selected area, but results in an enormous horizontal shift.

This addon is corrupted

Not working in andoird version

Installed, rebooted Firefox 54. Tried to capture. It sits there indicating it is capturing. Nothing happens. Perhaps I need to create an account, but I don't want to. Uninstalled.

Took a long time to capture page, got bored, did something else for a min, the working icon had stopped, and now I don't know if there is a screenshot somewhere or not!

scrolling webpage can't saved nor can it be saved to clipboard.

Couldn't find the picture after I took the shot. hmmmmm....

The positions almost never work. I place a text-box in one corner and it starts typing text in another corner.

Problematic capture: unless I want to use Diigo or Google, there are no other options because the Clipboard almost always fails.

Always full of bugs. Currently when I type captions, they are blank, and will only appear after I've finished. And then I realise it has run over and have to delete and repeat everything.

And probably my least favourite - all the typos and grammar errors. If you're making an add-on for English-speaking countries, get somebody to check your typos, otherwise it just makes you look extremely unprofessional.

When I selected a portion of the screen to capture in a Plarium.com flash-based game, the tool selected an area to the right of, and a different rectangular shape and size than I had selected.

Took me to a pointless editing page with nothing on it, then wanted me to sign-up to them to see my screenshot, which was hosted somewhere else. Uninstalling, too much hassle

Doesn't perform the basic function. Pays little attention to the area selected, captures pretty much random sections of the screen.

Too many steps needed to get to where I could copy the selected screen shot to the clipboard, and then it only held onto the data for 5 seconds -- not enough time to switch over to where I wanted to paste it.

New version looks horrible, can;t see tex I am typing, no way to save it as direct link, not usefull at all now, gonna have to remove ot and use other options

I was so happy, and it was very handy module to take screenshots, with new update it has been very slow, and froozen too much, when writing, you cant see the text.. etc too many bugs.. Removed, no more using it.............

Now its totally broken!

Where is URL's?
Why imagelinks SOOOOO LONG AND BIG?

永远都正在下载，永远进不了安装步骤。

Accidentally posted important info, now I can't delete it.

Desde que Firefox llegó a su versión 47.0.1: No se puede instalar el complemento, ya que muestra una incompatibilidad.
Sin hablar que su versión para Chrome cuenta con más características...

Since Firefox reach the version 47.0.1: It's impossible to install the add-on because it's incompatible.
Not to mention that the same add-on in Chrome have more features...