We had a concierge cabin in February 2016 on Disney Dream and we did get a cabana, which was very nice but I'm not sure I can justify the price again in the future for concierge or a cabana. At the time I booked concierge cabins were only a few hundred more than the verandahs, so it seemed a reasonable splurge. Now they are going for thousands more on some cruises, and I just cannot justify the additional cost.
On CC, I did enjoy the hammock but I felt itchy and I'm pretty sure there were sea lice or some sort of bug which made it difficult to enjoy the hammock. The shower was nice, and there was fresh fruit and snacks, as well as complimentary sunscreen, and a radio (but ALL of the cabanas have a radio, so it was annoying hearing the radio at the cabana next to us).
The best part was the beach which looked almost deserted in some of our pictures, compared to the main beach which was crowded with hundreds of people. We still had to stand in line to pick up our snorkeling gear, and if you do plan to snorkel the main beach area is better so you're not even spending time by the cabana beach. Same goes for the water slides. I just keep waiting in line for the water slides thinking I was wasting my money on the cabana. It also comes with a free bike rental, but again then you are not spending that time at the cabana. If you plan to just hang out in a hammock and relax, it's a wise investment. If you hope to be more active on CC maybe it's not worth it.
We had a safe but it broke and CC security had to come to open it. It definitely malfunctioned, not user error, because we had used it several times throughout the day to access our wallets. So it's nice to have a safe for security but it was a little stressful that it was not opening for us when we were ready to leave the island.