Should I Resand my Floor?

Should I resand my floor?

Refinished hardwood floor
AFTER
damaged hardwood floor
BEFORE

Every so often I will get a call or an email asking me if they should resand their hardwood floors. Some people discovered that they had hardwood floors underneath their carpeting or they bought a house with pre-existing hardwood floors.
Some of these hardwood floors are pretty beat up, gray, dull and dingy. A lot of people think that the floors are now ruined. But hardwood floors can take a lot of abuse, neglect and still can be re-sanded and brought back to almost original state to when they were first installed. As you can see by the pictures to the right of one such example.