Rated 3 out of 5 stars
You have to be very careful using scrapbook for important archiving because it can appear that you have saved a page that is in fact not captured in whole or in part. Moreover, what works in one version of firefox/scrapbook may cease to work with no warning. This inconsistency goes beyond failed captures that the developer may or may not consider a 'bug' as something not intended to be supported.
Scrapbook no longer successfully/reliably captures pdf files, pages with disqus comments, and who knows what else, so always manually verify captured pages and be prepared for alternative archiving methods. That is a nuisance but necessary if you don't want to lose information that may no longer be retrievable when the loss is discovered later.
The FAQ now says to capture pdf pages dragging from the main url (rather than the tab heading that used to work), but if you don't know that, forget, or automatically revert to the common capture method you will lose the page without realizing it. And despite the instructions for the special case of web pages displayed as pdf, capturing pdf pages may not work at all depending on what other plugins are installed -- you won't find the page in the 'data' folder in the file system either.
Likewise, when including the commonly used disqus comments on a web page, dragging from the main url may not work or work completely either, for example unpredictably truncating off some lines at the bottom of the last comment on the page or stopping at the first page of comments before "load more comments". Capturing by grabbing the tab will, at least for some sites incorporating disqus, not work at all, completely missing the disqus display of comments.
There are many useful features in scrapbook, operating within a very well thought out overall scheme, but the inconsistency in successfully saving pages, with no warning of failures or reliable guidelines for what can be counted on, is a real problem.