If you are mostly staying in Tokyo or Osaka and doing local day trips, the pass is a waste of money.
If you are only exploring one area (like just Kyushu or just Hokkaido), a Regional JR Pass is much cheaper and more effective.
A JR Pass is generally only worth it if your for individual trips exceed the pass price .
To help you figure out if it's worth it for your trip, tell me: What is your ? Which other cities are on your "must-see" list? How many total days will you be traveling?
The fastest bullet trains require an extra "supplemental" fee even with the pass; individual tickets let you book these directly. Pro-Tips for Timing