I just got back from the World last week and I got the the fireworks cruise for my wife's birthday. We did the Wishes cruise that has the music pumped into the boat and I have to tell you, I loved it.
It was a little different than I expected but it was really great. No crowds, no pushing and no mad dashes for the exit. The weird part for me was that the boats are not allowed to anchor so you tend to drift so the boat is constantly moving back to a center view. Don't get me wrong, you not drifting hundreds of feet, but all the boats seem to alternate where they are. Also, the boats traveling to and from the TTC are constantly going so you hear them blast their horns, but it's maybe once or twice during the show.
There is always a great view and they take you around bay lake and seven seas lagoon. It's almost a little creepy at night, but very cool. You also get to see a different view of the Poly and Grand Floridian at night.
I personally thought it was great. I have video of it and am going to try and post it to youtube.com. If I can, I'll update this thread.