We are a family of five who have cruised Carnival, RCL, and Disney. We have no particular allegiance to any line, and I wanted to comment on a few things from our trip. When I read reviews, I tend to disregard the ones that say everything was perfect and also the ones that complain about everything. I was particularly motivated to write this after reading someone say that their location in the dining room was so dark they couldn't see their food! So, here's some perspective...
EMBARKATION: The assigned boarding time was new to us, and we pondered just going earlier, but travel plans actually ended up getting us there about our time. We saw people who tried to line up prior to their time and were put in a line/waiting area for their time. As disappointed as they were, it is for a reason. This was the fastest we have ever boarded a ship. Curb to atrium in less than fifteen minutes. You essentially get all of your "paperwork" and id pictures done with a representative using a tablet-device. The result is a very speedy process. What slows it down is people who don't respect the boarding time window (and then they are the ones who complain!) We got onboard around 1:30pm and our room was ready. Major improvement, Carnival!
SHIP: We have been on the Dream class vessels several times and chose the Horizon to see the upgrades and the also were attracted by itinerary. The ship itself is beautiful, clean, and has several upgrades from the Dream class that are great. It is a little more muted in terms of decor throughout the ship...think classy, not glitzy....classy, but not stuffy. The LED sculpture is nice, but we missed the soaring atrium and glass elevators.