I loved the Pearl Crescent addon before FF57, but WE version is lacking some features:
1) capture the page without visual scrolling ***
2) use hotkey for capturing ***
3) save to Downloads\SUBFOLDER (like Downloads\PageSaver or something user-defined) ***
4) automatic filename increment postfix on name collision (instead of file overwrite) ***
5) some kind of solution to capturing of the fixed elements - for example the fixed footer panel (position:fixed; bottom: 0;) on "https://modnakasta.ua" is repeated on every scroll, instead of being drawn in the actual position (bottom: 0; in this case) or only once (as Screengrab addon does)

The features marked with *** were present in former versions of Pearl Crescent addon and/or are present in current addons from other developers (like mentioned Screengrab addon).

But Page Saver WE works faster on long complicated pages! ;-)