I run several installations of WordPress, and I've been struggling to find a video plugin that works reliably for auto-posting content. It seems I've finally found one in GrabMedia though.
Other plugins tend to either time out, mess up the posting, or just not play nice with my server. This one just installs and works. Select your post frequency, video category/keywords and who you want to post as, and you're good to go.
Now I can tend to my video posts once every week or so, and let the content run on auto-pilot. This is a huge time-saver!