Nicole:
If you do a search of this forum, there are a bunch of posts about Dine with Shamu. Some are positive, so not so much.
I did it last month with my DS. We were in a front row table along the ropes (pays to book early!). It was awesome to see such a large animal so close, but the Shamu show was short for the cost of the dinner (in my opinion). The buffet was okay.