We did this last week. My DW would say it was well worth the money and then some....
I thought it was very good, but it was the very HIGHLIGHT of her trip. She loves whales and she loved the dinner.
It absolutely POURED just prior to our dinner. I mean thunder, lightning, heavy rain..... It soaked the tables, chairs, everything. But that did not dampen (pun intended) the experience.
Like crjack said, the food is decent - not great, not bad. It's the whole EXPERIENCE that makes it worth it.