Definitely worth it! We took our kids to it this past October. They are only 3 and 1, so we didn't know if it would be worth it, but it was! There were no lines for the rides, which is great with little ones. Also, the kids loved wearing their costumes around the park. My 3 yo dd was especially excited to go on the Peter Pan ride since she and her brother were dressed as Tinker Bell and Peter Pan.
There's also a free family photo, which makes a great souvenir.
They also have trick-or treating, and there's a parade in which the Headless Horeseman (I believe that's the only time of year you can see him) makes an appearance.