we think Boma is the best dinner buffet at the World. The grilled meats and fish of the day are usually pretty "normal"--they just might have some type of spice rub or marinate that bring in the African flavors. They have a salad bar--greens are greens, but the toppers and side salads are just more creative than you tend to see at a traditional "american" salad bar. I think where it veers off to the unusual is the rest of the buffet--the sides, soups and hummus bar are all very authentic--and delicious! It's the only dinner buffet we have returned to multiple times.
we ate at the Clam Bake for the first time this last trip. we enjoyed it, but don't know if we would go again. It is very seafood heavy (although i would say the ribs are the best ones i have had so far at WDW). If you are going for the crab legs, I would say it's not worth it. I found them to be waterlogged, flavorless and not a lot of crabmeat for the work involved. There was a lobster casserole was very good.