The Holiday is Carnival's oldest and smallest vessel. With that, there are some things that cannot compare to newer ships. The children's facilities are not too large but the youth staff is excellent. Maintaining air conditioning in the buffet restaurant is a constant battle for the crew - mostly because of constant traffic which keeps the doors open. Water pressure and water temperature can vary depending on the time of day. It is a 20 year old ship and despite periodic refurbishments some things just can't be fixed. We have never had a problem with the cabin air conditioning.
All of that said, if you go into a Holiday cruise with your expectations properly set then you will have a good cruise. The Holiday is what cruising used to be before all the megaships came down the ways. It has the feel of a ship and not a luxury hotel. You can get just about anywhere on the ship in just a couple minutes. The dining rooms put out some very good food and have gracious waiters. Indeed, of all the Carnival cruises we have taken I think the Holiday has the best dining rooms.
The Port Of Mobile is a great place. The staff is very courteous.
And don't forget to try the corned beef at the deli station in the buffet restaurant.