Having travelled long haul worldwide for 30+ years and lived in Europe, the Middle East and the USA I have never been on a cruise and didn't really relish the idea. However, meeting UK family for New Year in Miami, with 14 & 15 year old kids we decided to take a short cruise over new year so at least the kids had a party in their back yard and we didn't have to go find one in an unfamiliar town. I was pleasantly surprised with the cruise and I do have considerable experience to compare to. Although the Imagination is one of the oldest and smallest of the Carnival ships, and the interior décor was tacky casino style, our cabin on Empress deck 7 was very clean, more room than expected, the bathroom was well planned, spotless and even had thick plushy towel robes and great shower. Our cabin steward was really awesome.
Food onboard was OK - some really good items, some so-so items. Wasn't really a fan of the waiters dancing and hated the Pirate and endless photo ops, but clearly a lot of the guests enjoyed it. For those complaining about the Mongolian Wok - I agree, the wait was horrible, food was ok-ish. We only did that once, lesson learned. Same with the junk food buffets. The dining room food was good (everyone turned up to eat at 8pm so long lines - we ate 7pm and almost no wait at all), service in the dining room, bar service on Lido deck, cabin service was very good. Spa service was excellent. I had almost no issues on this cruise. Did not see or smell anything particularly unpleasant, and did not think the cruise was overly crowded. No trouble, surprisingly, despite the partyers and NYE over-indulgence. Carnival DID nickel and dime you for everything and our bill for 2 adults, 2 (non-charging) teens was $1100 - we each drank probably 4-5 cocktails a day by the pool plus a glass of wine at dinner, 2 one-hour spa treatments and the rest was automatically applied tips. I can imagine if you party hard all day you are going to spend thousands and will probably be paying for it for a long long time... in which case I would recommend you just fly to Koh Samui or some other exotic destination for probably the same price and a lot longer in paradise.
Excursion in Cozumel on the Catamaran to the snorkeling and beach party was great! Beach was beautiful but looked like a movie set with guests arriving and leaving every hour.
One recommendation for Carnival - if you ARE going to run really dumb (but occasionally funny) competitions such as men vs women synchronized swimming contest, stretch yourselves a bit by giving $10 bar credits as prizes or something a little less worthless and tacky than 25c Oriental Trading medals or trophies. Your customers ARE providing the entertainment after all. Jeez...
Music was not current - lots of stuff from the summer, mixed stuff from the 80s and 90s and the usual line dance stuff like Wobble, Cupid Shuffle etc. A bit boring after a while. Have to give a shout out for the awesome guitar guy in the Atrium Bar area - you should put him in permanent place of the piano bar entertainment which was alarming at best.
Definitely recommend the Fast 2 Fun purchase - on and off the ship first gave us lots more time. Luggage was a bit of an issue - embarking, one of our tags came off and luggage took 8 hours to get to the cabin; disembarking someone jumped on our brand new, 1st time use, suitcase denting the main steel side struts like it had been hit with a sledgehammer. Carnival have offered to replace it, so no issue there either.
Generally, very enjoyable, no real issues, first cruise experience. Staff work too long hours.