Your hubscore number is from the quality characteristics before being published. It is then added to by people visiting and voting. The quality characteristics are: Lack of misspellings and grammar errors, number of words, pictures, videos, music, keywords, and links. I think that is all,, but there might be more.
The amount of work you do on it before publishing just adds to the score. Letting it set a day and then going back in to edit and refine will add to the score before publishing also. I try to write mine so that the score is as high as I can get it before publishing it. That is their mark of a quality hub. It is a big deal because a hub with low quality and quantity will have a low score.