If you feel that a substantial error has been made, then you should schedule an appointment. However, consider the following scenario: you schedule a hearing with the assessors, the assessors consider your position and adjust your assessment down $5,000. Applying the current tax rate of $0.77, the decrease in your annual taxes due would equate to $38.50.
To answer the question, you have to decide whether or not your time and effort is worth the potential change in taxes due.