I bought my Canon EOS 600D to shoot movies, and it just happens to be great at it. But if you spend a shooting day in the woods, you will see that you will not get by with 1 battery.
When I noticed that I needed an extra battery, I almost automatically surfed to Coolblue, because I knew that I could effectively use the battery the next day, and that was necessary, because we would be filming all night that night.
The Jupio LP-E8 is now indispensable, and ensures that I never have to stop spinning. The charging time is a few hours shorter than the time I need to empty the battery again, and with two batteries you can easily film all day long.
The price difference with the Canon battery was so big that I thought it would make a difference, but I don't notice any difference between my standard battery and the Jupio battery.
I am very satisfied with my purchase!