Thanks to all the posters that went before me with invaluable insight and advice. Paying it forward, here is my summary of our experience:
Aug 21- Embarkation
We had a 10:30-11 window to check in. Arrived curbside at 10:56, were on board in 18 minutes. Tip: I had a backpack with two bottles of champagne, a sixpack of zing zang bloody mary mix and it zipped right through. I didn't see security flagging any bags for a closer inspection. That day, and only that day, there were issues with the elevators as the center stack was reserved for delivering bags. Made our way up top for our first Guy's Burger for lunch. While eating we were approached with an offer to buy three bottles of wine at a discount. As we were on a casino offer with drinks included only when playing, we bought the package, 3 for $99, which we used for three bottles of Domaine Chandon durin g the week. Sailaway was a couple hours late. If any announcements were made as to why, we did not hear them. Too hot up top so we wound up going to our cabin (cove balcony 2373) and watching sailaway with one of our champagne bottles we brought onboard. Dinner that night in the DR - I had mahi, the wife chicken breast, both ok (pretty much the theme for the week, food was good, not great). After dinner the casino was mobbed as this was a Premiere players cruise. Way too smoky.
Aug 22 - At sea
Every day we walked the deck a couple miles to start the day. I had preordered a continental breakfast which we at on our balcony after the walk. We then spent some time at the Tides Pool aft before hitting the Sea Day brunch. Pancetta scrambled for me (one of the best things I ate all week). Filet and eggs for DW which she said was just ok. Tried our luck in the casino for a bit until the smoke got to us. Paytables on video poker were horrible and we got beat up all week on that. I kept afloat playing ultimate texas hold-em even though the odds were worse for that game than normal. This was elegant night. We began in the atrium bar listening to the Sunny Girls Trio, a fabulous group of violinists that we would catch every night they played. Dinner was Prime Rib (good), lobster (not good) and creme brulee (good). Caught some of the latin band in the Havana Bar later. Only problem is that with their doors opening to the outside it got hot in there. Fun band, though.
Aug 23 - At sea
Windy walk followed by bkfst on balcony. I should mention we had our Bose speaker with our spotify playlists downloaded and listened a lot on the balcony. Again some time at the Tides Pool followed by lunch at Guy's Pig and Anchor. Good BBQ, not great. Tip: on sea days, lots of lunch options on this ship other than the buffet. Guy's Burger, Guy's BBQ, Iguana burritos and tacos, salad in the Serenity, a small buffet in Ocean Plaza and of course the sea day brunch. Tip: Ocean Plaza has a small breakfast buffet which we wound up using after our walks from here on out. Quiet there, hardly anyone and the same food as in the Lido, just less of it. Did some afternoon trivia in Ocean Plaza, met some nice folks we teamed up with but not good enough to win the ship on a stick. Can't remember what we had for dinner that night but if you have my time dining, my suggestion is to at a time other than when the set time diners are seated (5:30, 7:00). Everything comes out of the same kitchen. Our service was always fine and never took more than an hour or so start to finish.
Aug 24 - Aruba
Walk was aborted due to rain which was the theme that day. After breakfast in Ocean Plaza, we walked off the ship to intermittent rain. The streets were very wet, with puddles in our way from time to time. The visit was shorter than we would have liked and would like to return but we hit our two goals at every port- drink the local beer (Balishi) and buy a Christmas ornament. After a lazy afternoon we had dinner at Cucina del Capitano. Best meal of the week. We had veal scallopini and braised short rib, excellent salads, Nona's meatball. I can't remember dessert but I am sure it was good. Well worth the $15 upcharge.
Aug 25 - Curacao
Really enjoyed walking around Willemstad, colorful, clean, walked across the Queen Emma floating bridge, through Rif Fort and just meandered. Might have been a sign when we saw a rainbow during our morning walk. Local beer and ornament, check, check. Back on board we had lunch from Guy's (me), Iguana - taco salad (dw). Tonight's dinner was probably the best of the week in the MDR, Filet for me and Garlic Shrimp for DW, grand marnier souffles for dessert. Pre-dinner as usual Sunny Girls and champagne.
Aug 26 - La Romana
Walk then bkfst in Ocean Plaza. Not much to see here, walked off and around the port area which was nice but same stuff. But we did get a beer (no ornament today) then returned to the ship. Salad and pizza for me from the Lido, taco salad for DW. Pool time around the main pool then just chilled. Dinner was turkey for me (good), seafood newburg for DW (OK). Casino was extra smoky tonight.
Aug 27 - Amber Cove
Second Dominican Republic stop and we enjoyed a half day around the resort style pool. Very nice, good service, beautiful background. We did a 5 bottle bucket of Presidente (seeing a trend here?), and picked up an ornament from one of the shops. Tonight's dinner was at Ji Ji's Asian. Good but I think I expected better because of the raves I had seen on you tube.
Aug 28 - At Sea
Heading home. I have to remark on how stable this ship is. Seas were mild the entire week but even so you usually feel the vibrations and movements more than we did this week, not even arriving and departing. We had a relaxing day with little to report. Dinner of course was the big production, singing, dancing, bringing out the chefs, etc. A bit over the top but we did not mind. Tonight the Sunny Girls (by now only two, I guess one was sick) after dinner with our last champagne bottle, a short visit to the casino then off to bed.
Aug 29 - Debarkation
We chose walk off and were in our car headed home at 8:30.
A couple notes:
Happy to answer questions but as you can see from my report I won't be of much help regarding shows. Didn't attend a single one.
Overall, the trip exceeded our expectations. This was our third Carnival but by far the biggest ship and we were impressed with the Horizon. We think our room was larger than any other we have had except maybe the aft balconies on the Norwegian Getaway. We weren't sure about the cove balcony and had no choice in picking it as we were on a casino deal but wound up really liking it. Service everywhere was excellent. There were complaints in the casino about drink service but the place was jammed and the servers were hustling. I always tip a buck and never went thirsty. The ship was spotless and people were constantly cleaning.
I hope this helps some future cruisers. Enjoy!