My family has been on a couple Carnival cruises before this one. I've broken up the main categories into subsections. Go straight to the bottom for a review of the Cheers drink package.
[Ship]
Although the Magic is one of Carnival's larger ship sizes many of the places people like to congregate for shows or activities are easily accessible and packed close together so you don't have to travel long distances in order to get where you want. Having a bigger ship also means more fun activity options are available and despite having more people on-board you won't find most locations are overly crowded by any means.
Great cabin with large wrap-around balcony however the balcony floor was dirty a majority of the time because when the decks above were cleaned all the mucky water flowed down onto the balcony and chairs. The aft-view cabins are the only ones with balconies that protrude with no roof. The fridge didn't seem to function at all, as all our water was lukewarm for the entire trip, regardless of being in the room or not. Otherwise the room was awesome (good space, comfy bed, good bathroom).