I am a first-time cruiser and had heard mixed reviews about Carnival, but decided to try it myself anyways. I am a good-natured person who is not hard to please and generally has a good time wherever I go. I had fun on the Carnival Liberty, but it was more because I made it fun with the person I was with, rather than being overly impressed by the ship.
Good:
Embarkation: We had never been on a cruise so we had no idea how embarkation worked, but it was very easy. A lot of other reviews said it took forever, but that wasn't the case with the Carnival Liberty when I went 10/20-10/27. We were on the ship in no time and didn't have to wait in many lines, though we did get there early. I don't know how it was for people who got on later.
Carnival Liberty cabin 6442 was perfect. It was an extended balcony aft-view and worth the extra money. Beautiful balcony. The room was perfect for 2 people. Bigger than I expected on a cruise ship. Thumbs up.