Short version: This works where others don't, and has all the features to do it right.

Longer version: It downloads embedded vidoes that other things won't, it downloads them fast, it downloads with reasonable filenames in a place of your chosing in one click, and there are lots of fine-tuning controls if you want them.

Story version: I used to use Chrome for downloading videos from a big-name Japanese video site (FC2) to which I have a subscription. Then, at some point, ALL of the video download plug-ins for it stopped working. Eventually, I went to see what Firefox had available, found this plugin, and am back in business. Better yet, it does a better job of letting me one-click download videos than any of the other big-name plugins I tried.