I cruised on the Spirit in 2007 and cruising again on her in 2009. So as you can tell I liked her.
The Spirit does not at all look old. It just got out of drydock so it should be all nice and new.
The Spirit is about 88,000 tons but has about 2,100, so you have a lot more space per person.
Also the Spirit Class has the best layout of any Carnival ship.
So there are many reasons why the Spirit is a great ship.
If you have any specific questions, feel free to ask me.