We've done both for both breakfast and dinner. Cape May is our traditional last day breakfast and Chef Mickeys is traditionaly our first day at WDW dinner. So....we much prefer CM's for dinner over Cape May. We had dinner there a few years ago. My father and step-mom drove up to be with us for a few days, so wanted a nice spot close to BW. Being from NE, we figured we would try the clam bake at Cape May. Now....I'm not a big seafood eater, but the rest of the group was. I did find some prime rib to eat, but it was just okay. Everyone else was very disappointed with the seafood. They weren't crazy about the clams especially. We all agreed that it wasn't someplace we would go back to.
CM's for dinner is fine. The food really isn't much different than the other buffets you will see. My dh looks forward to dinner there every visit...so I am happy to oblige. Yes, it does get noisy and crazed in there...much more so than Cape May. But, that's what happens when you add characters. No characters at dinner at Cape May so it's a bit quieter.