I've done both and I'd definitely recommend Ohana over the Spirit of Aloha (Luau). You can see Wishes from Ohana and I believe they play the music. At Spirit of Aloha (if you have the 8:15 showing) you can see it as you check in and wait to be seated, but they do not play any of the music to go along with the fireworks.
I had a bad experience with Spirit of Aloha so that's why I'd say Ohana is better. With Spirit of Aloha, we purchased Tier 1 seats and were seated all the way in the back of the Tier 1 section with a post obstructing half of the stage (which was really upsetting and irritating). The show felt like it dragged on for forever. They started it with some cheesy story and then about an hour or so later the actual luau started (which wasn't that great either to be honest). The food was just "meh" considering the selection was somewhat small. Overall, it isn't worth it for the price that they are charging.
With Ohana, the food is great as is the atmosphere. The food consists of a noodle appetizer, pot stickers (which were fantastic), a vegetable dish, and pineapple bread. The entree portion of the meal has chicken, pork, steak, and shrimp. Overall I think it's worth the price as opposed to Spirit of Aloha. I've returned to Ohana at least 4 times and it's always been perfect.