We left on September 3 from Miami. We stayed at the Springhill Suites near the airport the night before. A cab for 4 to the cruise port cost $35, which was less than $10 apiece for the crowded hotel shuttle.
Embarcation was pretty easy. First tip: Make sure you get your boarding group card as you enter the registration room. There was a lady handing these out as you entered, but, she was quite friendly, and we passed her by while she chatted up some other cruisers. We ended up boarding at least 20 minutes later, since we didn't get a card until after we registered.
Dinner Saturday evening was our first indication that things had changed at Carnival main dining. Rather than a night by night rundown, we ate at the main dining room 4 nights, Harry's twice, and Lido Buffet one night. I might seriously consider going to Harry's 3 or 4 times on the next cruise. The service is still very good in the main dining room, but, (apart from the melting cake and bread pudding) the food has become quite mediocre. The comfort food menu will remind of Cracker Barrel. Fried chicken is quite good, but, it is fried chicken. I'd take Cracker Barrel pot roast over the cruise version. My 4 main dining meals were Flank Steak (cooked right, but, a tough steak), ChateauBriand (also pretty chewy), Pot Roast, and a cheeseburger. Note, that I ordered the Cheeseburger to see if it was different from the one served at the Lido Grill. It was not. If you are thinking that this sounds mundane, I think I agree. My wife did really like a Basa (fish) dish that had apparently won some award for cruise main dining. I ate the warm chocolate melting cake for dessert all 4 nights. My wife and our friends raved about the bread pudding the one night it was served.
6450 is in the back of the boat (sorry, don't know difference between port and starboard). It is parallel with the hallway (while all other cabins are perpendicular). This creates a double balcony. If you want to trade a sofa for a larger balcony without paying extra, this is a very good cabin. One floor down to Promenade deck. 3 floors up to Lido. So, its a good cabin to avoid elevators. I'd get this cabin again.