If you like deep fried, sugary things you will enjoy the Tonga Toast. Personally, it is too heavy for me. My solution is to order it grilled instead of fried. It is much lighter (although it is still huge and very filling) and much less sugary as the cinnamon sugar does not stick as well when it is grilled. I absolutely love it grilled while there are many who prefer it in its original form.
As the previous poster said, if you want to try the Tonga Toast but save a little money, head to Captain Cook's at the Poly instead. It's the quick serve location so the food is less expensive but it's the same Tonga Toast they serve upstairs at Kona.