I enjoy the old 1 to 5 star rating for YouTube more since it was more accurate. There are some videos I like, but also don't like, so I gave them a 2 or a 3, and there are some videos which are worth a 4 because they were not amazing and not worth a 5 out of 5 stars.
For videos which had bad audio, and poor video quality, or the video was too long, I gave them a 1 star.
I feel the like and dislike poll is more suited for sites like Facebook, and Google Plus where people are less likely to score a post or photo out of 5 stars.