I like the Holiday a lot. It is indeed the oldest ship in the Carnival fleet, and therefore shows some wear and tear and is rather quaint when compared to the newer ships we see these days. But the Holiday offers an enjoyable cruise on a ship that allows you to maintain contact with the sea. It is currently under charter to FEMA and will undergo a refurbishment prior to returning to service with Carnival.
To me it is worth the price, but you have to have your expectations set properly and realize the Holiday is a 20 year old vessel. Do that, and you will have a great time.
Here is my last review of the Holiday: Holiday Review June 2005