I've eaten there, but since I don't like seafood I don't think I'm qualified to judge that part of it.
The other food on the buffet was very good, however, as were the desserts, for what that's worth.
If I'd realized it was a seafood buffet when I made the ADR, I probably would have chosen somewhere else. I knew it was a buffet, just not that it was primarily seafood. I picked it because we were staying at the Dolphin while my husband was at a conference and it seemed like a convenient location for a character dinner for my daughter and me.
Hope someone who likes seafood will give you a better response!