A caveat: I don't know Hingham at all, so I can't comment on what may have happened with property values there.
However, what you should do is determine what the true value of your property is, and how that compares with the assessment. A Realtor can help you pretty easily with that. Or, you can probably do the research yourself.
If you find that your tax assessment is too high (even if it's a gray area), certainly appeal. The worst case scenario is that you lose, you've invested some time in the effort, and you pay the same taxes you'd have paid without appealing. The best case scenario is that you win, you pay less in taxes than if you hadn't appealed, and you learn a lot about how local government and the assessment process works.