We spent 24 days on the Horizon. I realize that this was an inaugural cruise and there are many "kinks" to be worked on but Carnival has been in the cruise business a long time and some "kinks" should have been obvious.
They are already aware that the main showroom (Liquid Lounge) is not big enough and the seating arrangement is ridiculous. Deck 4 is better than deck 5 for line of sight and you must arrive 30 minutes before the show so you can get a seat.
The Guest Relations desk is next to the atrium. There is constant music or performances going on which means the guests and the employees can not hear each other speak.
Great location. Good cabin stewards. Typical balcony cabin on Carnival