First, I need to address this comment: "The last HAL cruise we took (Westerdam, Jan. '08) was after Carnival had full ownership of the line and you could tell it had been "Carnivalized" to some extent." Carnival Corporation acquired HAL in January 1989... far from recent. So, any perceptions of changes in the line are certainly not attributable to a change in ownership. Let's get beyond that, please. OK, now for the real reason I'm responding: The main difference is that HAL has an As You Wish Dining (AYWD) option whereas Celebrity hasn't gone this route (to the best of my knowledge--someone please correct me if that's not so.) Of course, traditional dining is still an option on HAL. I seldom go to the buffet, so I can't provide much of a comparison there, yet Celebrity does offer a less casual experience in the buffet for dinner for a modest charge. I found them to be comparable in most ways, yet this is subjective. Is there anything specific you'd like to know?