youtube doesn't have slow motion mode for playback. i can't c it clearly....
anyway, we always render a file sequence first, & then put it into comp software (such as After Effects). finally, render a movie for ouput, that's it
It's so important to render a sequence (eg. tif, tga). It can save ur time in several conditions:
1. u can check ur image that have anything wrong after 1st frame rendered.
2. If ur computer have any error or unstable situation, ur batch render cannot continue anymore. U will be lost all the render time for movie format.
3. For a more efficiency production, render different frames in a render farm or home network. It can save ur life!