We've actually been to Capone's about 3 times in about 15 years. We saw the holiday/Christmas show about 3 years ago. We had a great time - the show is corny/funny - very cute. The buffet is definitely nothing to brag about - but it was edible - definitely second to the show. They keep your glass filled with your beverage of choice (beer and wine included when we were there last). There is some audience participation - they recognize special events. Again - all in all a fun night!
My DD and I have been looking for something to do on Christmas eve - and Capone's is on our short-list!
I'm sure you will have a great time.