So Far I have had good results with the extension. I'm able to download any video at 1280-720, mp4 or webm format. The speed was impressive at first but slowed down to moderately slow. I doubt the extension is at fault here and I suspect either my ISP (Comcast) or google not sure but I'm giving the author 5 stars.

update: 12.30.2019:

I added an extension called "Magic Actions" it sometimes allows the download button and sometimes not. Now it is showing a two download buttons.

It does what it's supposed to do.
Absolutely love it

640x360 px only

no activa el boton de descarga ya no funciona

don`t work

Es incapaz de descargar ningún vídeo.

funktioniert ja wunderbar! Habe im Downloadordner sofort den Film. Allerdings nicht zur Wiedergabe, da nur Fehlermeldungen kommen: "Nicht abspielbar". So hatte ich mir das immer schon gewünscht! Deinstalliert