We have cruised twice before, once on Carnival (10 years ago) and once on the Norwegian Star (last year). While we don't dislike Carnival, we both agreed that NCL was just nicer overall.
Getting to the Port of Miami:
If you don't mind taking public transportation and some walking you can get from Ft. Lauderdale to the cruise port for $5 per person. We had two carry-ons and a backpack. If you are taking more than just carry-ons this may not be the best option. Here is how we did it. We landed in Ft. Lauderdale (FLL) airport and took the free shuttle to the Tri-Rail station. The Tri-Rail runs from West Palm Beach in the north all the way to Miami. For $5 you can ride the Tri-Rail to the Metrorail station. At the Metrorail station exchange your Tri-Rail ticket at the ticket window for an Easy Ticket at no cost. The Easy Ticket allows you to ride the Metrorail all day. Take the Metrorail to the Government Center station and then hop on the Metromover (Omni line-blue). The Metromover is free. Hop off at the Freedom Tower station and walk 1 mile over the bridge to the cruise pier. Overall, it took about 2.5 hours to get from the FLL airport to the cruise pier.
Embarkation took too long and was disorganized. On NCL when checking in there was someone to take your carry-on luggage so you didn't have to walk it on. On Carnival, everyone who had just carry-on luggage had to drag it onboard themselves. And since you can't get to your cabin until 1:30 p.m., there were people dragging luggage everywhere. This made the embarkation process cumbersome and slow. You'd think Carnival would figure out a better way to do this.
Our only complaint is that the cabins have paper-thin walls. You can hear everything that is going on in the hall and in the adjacent rooms clear as day. Also, our cabin was located right above the casino, which was loud. The bed was comfortable and the overall size of the room was standard.
The food was not good the first couple of days on the Valor-- dry and flavorless. As the week progressed the food did improve, but it wasn't anything exceptional. The buffet (Rosie's) is surprisingly limited and there is really only one option for late-night dining (the pizza station). On the NCL Star there were two 24 hour places and the buffet selections seemed to be twice as many. Nevertheless, the Mongolian BBQ and Burrito bar on the Valor were good. Fish and Chips had a couple of good menu items but was only open noon-3:30 p.m. daily. Our assigned dining room was the Lincoln. The wait staff was attentive and friendly; the food was hit and miss. The chocolate melting cake was good, but not as amazing as others made it out to be.
The tendering from shore was disorganized. It took way too long to get back to the ship.
The beaches here are awesome!! We spent several hours on Sea Grape beach. Sea Grape is the public beach that has the Calico Jacks bar/grill on the north end. This is a nice beach with lots of room and soft white sand. As others have mentioned it is much cheaper to get to the beaches by public bus. The buses are actually minivans that come around every 10 minutes or so. The cost is $2.50 per person each way regardless of the distance you are travelling. Routes #1 and #2 both go along Seven Mile Beach. The minivans are marked with big colored stickers with the route number and the letters WB. The drivers will usually honk as they drive by. If you want them to pick you up, wave your hand. When you want to get off just alert the driver and he/she will pull over. I believe you can take the public buses all the way to Hell and the Turtle Farm.
I can confirm that there is FREE WiFi available at the public library at Heroes Square, just two blocks from the cruise ship pier. The SSID is GCLS (Grand Cayman Library System). We spent several minutes checking email and chatting with family back home. The bandwidth wasn't high enough to do Skype or Google Voice, but we were able to send texts. The public buses run right in front of the library so it was easy to head to the beach after using the internet.
Again, Carnival is disorganized. They give preference to those who have booked post-cruise excursions in Miami. Three lanes were dedicated to them while only one lane was used for everyone else. As you can imagine, people started getting angry because the main line was getting longer and longer, while the other lines were not even being used. What should have taken 15 minutes to get off the ship took 45 minutes.
The activities and shows on the ship were ok. Here again, NCL had better shows and more varied activities. The specialty drinks were small and expensive. The cabin stewards did a good job of keeping our cabin clean and tidy. All of the staff on the Valor was nice. I was impressed with their patience in tolerating some rude and demanding guests.
If you are on a tight budget, the Carnival Valor will certainly be worth the money. If you are looking for a more upscale cruise experience, book with another cruise line. We wouldn't mind sailing on Carnival again when money is tight, but look forward to trying other cruise lines also.