I just did the cruise for the 1st time Friday night. It was a surprise gift for my DH's 30th b-day (his absolute favorite is IllumiNations), and our parents came and surprised him as well.
It was a beautiful night, the ride around the waterways was great, and it was a nice, relaxing, and beautiful way to pass the time before the show versus holding down a piece of concrete.
As for the view? Is it good - yes. We could see the fireworks and the globe perfectly. The only thing I didn't see quite as well as I had earlier in the week from outside Italy were the water features. It was cool to be able to fill the heat from the fire at the beginning, and it is a neat vantage point. Plus, you don't have to fight all the people exiting at the end!!!!
Would I do it again? For a special occasion, yes. For any other night, I'll probably just watch it for free. I do think it is something you should do once if it interests you.