I really like this extension. It pretty much has all the features of other ao3 extensions you may find on here and more. I especially like the fetch marked for later/bookmarks option and the metadata it collects is incredibly thorough. This being said it is very laggy on AO3. Badges take a long time to be added after selecting them and it significantly slows down scrolling, especially if you have more than one tab open.

I'm really loving this extension so far! I was looking for a way to better organize my "Marked for Later" list and this is perfect! The fact that you can import the list right from AO3 is a game changer. I can't recommend this extension enough!