We did an Illuminations cruise and have another scheduled for this year. We really enjoyed it and think it was worth the money. For Illuminations the boat view is great. They park the boats under the bridge by France and we had a direct view of the fireworks. We were at eye level with everything an it felt up close and personal.
We haven't taken a Wishes cruise, however we did do the Pirates and Pals fireworks cruise and I didn't like watching Wishes from out in the middle of Bay Lake. You got to see the fireworks above the castle and the music was pumped in, but it was too far away from me. It lost something not seeing the castle up close and all the surroundings. I think a better way to watch Wishes is the Wishes dessert party.