Are You Middle Class?

In class a few weeks ago, we took a poll of the class to see which class we thought our families were in. In an article from US News, they break down the average "middle class' family and answer the question, "how to gauge your middle class status.
I think it is interesting to see that what this author believes are the marking points for a middle class family. Everything from your income to your free time is factored into the calculation. In our class, we discussed the middle class and many of us thought that there were gray areas in figuring your class level. However in this article, there seems to be set distinctions.

In my opinion, I think that there are many grey areas, however, the bench marks that the author of this article present seem to be realistic and broad enough to cover most families that fall under 'middle class' status.

Do you think that the specific numbers and statistics that the article brought up are reasonable to gauge class status or is class something based on opinion and not the numbers? Does this article change your idea of what class your family is?