We took a wishes cruise last September. It was great!
We left from the Polynesian, the boat driver was really knowledgable about Disney history and the design and layout fo the parks/ layout and told great stories. Took us for a tour around the 7 seas lagoon before it got dark and then set up for the fireworks. Then after the fireworks the electric water pagent went right by us! There were drinks and snacks available on the boat, but we had just eaten so we didn't have many, but it seemed like there were plenty.
I thought it would be a once-in-a-lifetime thing to do, but my husband loved it so much he thinks it should be something we do every time.
The other really nice thing is that it was just our family on the boat - there were 8 of us along on that trip - and it was just a special moment for all of us to be together, to enjoy the fireworks and the boat ride. Although we were in Disney at a low-crowd season, this made it really seem special that we weren't surrounded by others oohhing and ahhing right on top of us too!